WO2016039308A1

WO2016039308A1 - Seal structure for rectilinear motion system, and piston member

Info

Publication number: WO2016039308A1
Application number: PCT/JP2015/075390
Authority: WO
Inventors: 裕道脇
Original assignee: 株式会社ＮｅｊｉＬａｗ
Priority date: 2014-09-08
Filing date: 2015-09-08
Publication date: 2016-03-17
Also published as: JP2016056847A; JP6528302B2

Abstract

Provided is a seal structure for fluid, the seal structure being applied to a rectilinear motion system. The seal structure is provided with: a piston member which forms a part of at least a piston body and which has an insertion hole, etc., the insertion hole allowing a rectilinearly movable rod to be inserted therein; an annular outer seal fitting section which is formed in the outer peripheral surface of the piston member, has a smaller diameter than the seal section, and is continuous with either of a pair of axially facing end surfaces; an annular outer seal member which comes into contact with the outer seal fitting section of the piston member; and an outer seal retaining member which is disposed near an end surface of the piston member and which axially presses the outer seal member. As a result, the seal structure for the rectilinear motion system can be assembled easily and has high sealing performance.

Description

Linear structure seal structure, piston member

The present invention relates to a piston member that receives an external force and a fluid seal structure in a linear rod that holds the piston member in a linear motion system.

There are many linear motion systems that create reciprocating motions according to the purpose, such as hydraulic cylinders, Bingham dampers, air cylinders, and shock absorbers. These linear motion systems often have a piston member that receives fluid pressure and a linear rod that holds the piston member. The piston member is used to control the reciprocating motion, and the reciprocating motion is linearly moved. The power is output or reduced through the rod.

For example, in a hydraulic cylinder shown in Japanese Industrial Standard JIS B 8368, a piston member and a linear rod are arranged in a cylindrical tube. The hydraulic pressure is supplied into the tube to cause the piston member to perform a desired reciprocating motion, and the motion is taken out from the linear motion rod.

¡Screw is generally used to fix the piston member and linear motion rod. Specifically, a male screw is formed in the vicinity of the end of the linear motion rod, and in a state where the piston member is fitted, a female screw body is screwed into the male screw and fixed so as to sandwich the piston member. It has a structure.

When fastening the female screw body, a washer (washer) or cushion sleeve is inserted around the linear motion rod. These members protect the piston member from buckling and scratches at the time of fastening, and conversely suppress the loosening of the screw body by positively pressing the piston member against the piston member.

Also, in order to improve the sealing performance of the working fluid in the tube, a piston ring (outer seal member) is provided on the outer peripheral surface of the piston member. A synthetic resin material is generally used for the outer seal member, and the outer seal member is forcibly fitted to the fitting groove extending in the circumferential direction on the outer peripheral surface of the piston member while elastically deforming the outer seal member toward the expansion side. Combine.

Similarly, an inner seal member is also provided between the linear motion rod and the piston member. Generally, the inner seal member is also made of a synthetic resin material. The inner seal member is fitted to the inner groove of the piston member in the circumferential direction while elastically deforming the inner seal member to the contraction side. Let

In the case of a structure in which the seal member is fitted to the groove of the piston member while being elastically deformed, the synthetic resin for the seal member must be selected with a high stretchability, and there is a problem that the degree of freedom in material selection is narrow. there were. Therefore, the friction resistance is high and the working fluid is hardly deteriorated, but even if there is a material, it cannot be used for the seal member.

Also, when the seal member is elastically deformed to be fitted to the piston member, there is a problem that the seal member is cracked or broken. On the other hand, when trying to reduce the amount of elastic deformation of the seal member at the time of installation, the fitting groove of the piston member has to be shallow, and there is a problem that the axial engagement between the piston member and the seal member becomes weak .

Also, since the external force of the working fluid is repeatedly applied to the piston member, the internal thread gradually loosens and the piston member and the linear rod are disengaged. In order to prevent loosening of the internal thread body, the internal thread body is tightened strongly, but this is not an essential solution, and there is a problem that the piston member and the linear motion rod are likely to be subject to fatigue failure. .

In order to prevent loosening of the female screw body, for example, a snap ring may be fitted on the outer side of the female screw body. If the snap ring is used, it is possible to prevent the female screw body from falling off from the shaft portion, but there is a problem that the female screw body cannot be prevented from loosening. Further, since the snap ring is relatively thin or thin, the snap ring is easily broken and is difficult in strength.

In addition, in the case of a structure in which a step is formed on the linear motion rod and a piston member is brought into contact with the step and is fixed by being sandwiched by a female screw, the diameter of the linear motion rod needs to be reduced stepwise toward the shaft end. is there. As a result, the diameter of the male screw formed at the outermost end of the linear motion rod is the smallest, but all forces acting on the piston member must be received by this male screw. As a result, it becomes difficult to increase the cross-sectional area (diameter) of the male screw alone, and in order to provide a step, the body side of the linear rod must be designed to be thicker than necessary. There is a problem that the cost increases due to the accompanying increase in weight, increase in processing amount, and the like.

The present invention has been made by the inventor's earnest research in view of the above problems, and provides a seal structure and the like in a linear motion system that can be easily assembled and can improve seal performance. With the goal.

The present invention that achieves the above object includes a piston body that is accommodated in a tube so as to be movable in an axial direction, and the linear motion rod that holds the piston body and interlocks with the reciprocating movement of the piston body. A fluid sealing structure applied to a linear motion system, comprising at least a part of the piston body, an insertion hole into which the linear motion rod is inserted, and an outer peripheral surface facing the inner peripheral surface of the tube A piston member having a seal portion that restricts the movement of the fluid in the vicinity of the inner peripheral surface, and formed on the outer peripheral surface of the piston member, having a smaller diameter than the seal portion, and in an axial direction An annular outer seal fitting portion that continues to any one of a pair of end surfaces that face each other, an annular outer seal member that contacts the outer seal fitting portion of the piston member, and the piston portion Is arranged near the end faces of, characterized in that it comprises a outer seal holding member for pressing axially said outer seal member to the outer seal fitting portion, a sealing structure of the linear motion system. The outer seal fitting portion can be configured to form an annular step portion having a bottom surface portion set to have a smaller diameter than the seal portion.

In relation to the seal structure, the outer seal holding member is fixed to an end surface of the piston member.

In relation to the seal structure, the outer seal holding member has a female thread portion for a retaining member that is screwed into the male thread portion of the linear motion rod.

In relation to the seal structure, a first male screw spiral groove and a second male screw spiral groove having different lead angles and / or lead directions are formed in the male thread portion of the linear motion rod, and the piston member The basic hole is formed with a female thread portion for piston that is screwed with the first male screw spiral groove of the linear motion rod, and the female thread portion for the holding portion of the outer seal holding member is threaded with the second male screw spiral groove. It is characterized by combining.

In connection with the seal structure, the outer surface of the outer seal fitting portion is configured to have a tapered shape with a large diameter on the seal portion side and a small diameter on the end surface side.

In relation to the seal structure, the pressing surface of the outer seal holding member that presses the outer seal member is formed in an annular taper shape having a smaller diameter in the pressing direction.

In relation to the seal structure, an annular inner seal member disposed between the linear motion rod and the piston member or the outer seal holding member is provided, and the piston member or the outer seal holding member is A basic hole into which the moving rod is inserted, and an annular inner seal housing hole that is larger in diameter than the basic hole and continues to one of a pair of end faces facing in the axial direction of the inserted member. The inner seal member is in contact with the inner seal accommodation hole.

In relation to the seal structure, a stepped portion or a tapered surface that engages with the inner seal member in the axial direction is formed on the outer peripheral surface of the linear motion rod.

In relation to the seal structure, the peripheral surface of the inner seal accommodation hole is a taper structure in which the basic hole side has a small diameter and the end surface side has a large diameter.

In relation to the seal structure, the linear rod is formed with a rod-side cooperation region having a non-circular cross section when viewed from the axial direction in the shaft portion having the male screw portion, and the piston member is inserted into the insertion portion. In the hole, an internal thread portion that is screwed with the external thread portion, and a piston side cooperation region that has a non-circular cross section when viewed from the axial direction are formed, and the rod side cooperation region and the piston side cooperation region are external forces. It is characterized in that it has a structure that engages with each other in the circumferential direction while allowing relative rotation by.

In relation to the seal structure, it comprises at least a part of the piston body, and includes a linkage member having an insertion hole into which the linear motion rod is inserted. A rod-side cooperation region having a non-circular cross section when viewed from the axial direction is formed, and the insertion hole of one of the piston member and the cooperation member has a non-circular inner periphery so that the rod side A piston-side cooperation region that engages with the cooperation region in the circumferential direction is formed, and a piston internal thread portion that is screwed with the male thread portion of the linear motion rod is inserted into the other insertion hole of the piston member and the cooperation member. A relative rotation prevention mechanism is formed between the piston member and the cooperation member. The relative rotation prevention mechanism engages both in the circumferential direction.

In connection with the seal structure, the linkage member also serves as the outer seal holding member.

In connection with the seal structure, the basic hole of the piston member is formed with a female screw portion that is screwed with a male screw portion of the linear motion rod.

The present invention that achieves the above object includes a piston body that is accommodated in a tube so as to be movable in an axial direction, and the linear motion rod that holds the piston body and interlocks with the reciprocating movement of the piston body. A fluid sealing structure applied to a linear motion system, comprising: an inserted member that constitutes at least a part of the piston body and has an insertion hole into which the linear motion rod is inserted; An annular inner seal member disposed between the insertion members, and the insertion hole of the member to be inserted has a basic hole into which the linearly acting rod is inserted and a diameter larger than that of the basic hole. And an annular inner seal accommodation hole that continues to any one of a pair of end faces facing in the axial direction of the inserted member, and the inner seal member is in contact with the inner seal accommodation hole. Features A sealing structure of the linear motion system.

In relation to the seal structure, the inserted member is a piston member having a seal portion that restricts movement of the fluid in the vicinity of the inner peripheral surface on the outer peripheral surface facing the inner peripheral surface of the tube. The piston member has an annular outer seal fitting portion formed on the outer peripheral surface, having a smaller diameter than the seal portion, and continuing to any one of a pair of end surfaces facing in the axial direction. And an annular outer seal member that is in contact with the outer seal fitting portion of the piston member, and an end surface of the piston member that is disposed in the vicinity of the end surface of the piston member. And an outer seal holding member that is pressed in the axial direction.

In relation to the seal structure, it comprises a second inserted member that constitutes at least a part of the piston body and has an insertion hole into which the linear motion rod is inserted, and the male thread portion of the linear motion rod includes: A first male screw spiral groove and a second male screw spiral groove having different lead angles and / or lead directions are formed, and the basic hole of the inserted member is threaded with the first male screw spiral groove of the linear motion rod. An internal thread portion is formed, and an internal thread portion that is threadably engaged with the second external thread spiral groove of the linear motion rod is formed in the insertion hole of the second inserted member.

In connection with the above seal structure, the outer seal fitting portion has a taper structure in which the peripheral surface has a large diameter on the seal portion side and a small diameter on the end surface side.

In relation to the seal structure, the linear rod is formed with a rod-side cooperation region having a non-circular cross section when viewed from the axial direction in a shaft portion having a male screw portion, In the insertion hole, an internal thread portion that is screwed with the external thread portion, and a piston side cooperation region that has a non-circular cross section when viewed from the axial direction are formed, and the rod side cooperation region and the piston side cooperation region are It is characterized in that it is structured to engage with each other in the circumferential direction while allowing relative rotation by an external force.

In relation to the seal structure, the shaft includes a second inserted member that constitutes at least a part of the piston body and has an insertion hole into which the linear motion rod is inserted, and the linear motion rod has a shaft having a male screw portion. The rod side cooperation region having a non-circular cross section when viewed from the axial direction is formed in the portion, and the inner periphery of the insertion hole of one of the inserted member and the second inserted member is non-circular As a result, a piston-side cooperation region that engages with the rod-side cooperation region in the circumferential direction is formed, and the insertion hole of the other inserted member and the second inserted member has the insertion hole of the linear rod. A female screw portion that is screwed with the male screw portion is formed, and a relative rotation preventing mechanism that engages both in the circumferential direction is disposed between the inserted member and the second inserted member.

In connection with the seal structure, the basic hole of the member to be inserted is formed with a female screw portion that is screwed with a male screw portion of the linear motion rod.

The present invention that achieves the above object is a piston that is accommodated in a tube so as to be movable in the axial direction, is fixed to the linear motion rod in the tube, receives the pressure of the fluid, and transmits it to the linear motion rod A member, which is formed on at least one of a pair of end surfaces facing in the axial direction, facing a pressure receiving surface for receiving the pressure of the fluid, an insertion hole into which the linear motion rod is inserted, and facing an inner peripheral surface of the tube A seal portion that is formed on the outer peripheral surface and restricts the movement of the fluid in the vicinity of the inner peripheral surface, and is formed on the outer peripheral surface and has a smaller diameter than the seal portion and continues to the end surface. An annular outer seal fitting portion, and an annular outer seal member is configured to be disposed in the outer seal fitting portion.

In connection with the piston member, the peripheral surface of the outer seal fitting portion has a taper structure in which the seal portion side has a large diameter and the end surface side has a small diameter. That is, the bottom surface portion forming the annular shape of the outer seal fitting portion is configured to be tapered.

In relation to the piston member, the insertion hole has a basic hole into which the linear motion rod is inserted, and an annular inner seal accommodation hole having a larger diameter than the basic hole and continuing to the end surface. Thus, an annular inner seal member can be arranged in the inner seal accommodation hole.

In connection with the piston member, the peripheral surface of the inner seal receiving hole has a tapered structure in which the basic hole side has a small diameter and the end surface side has a large diameter.

In connection with the piston member, the insertion hole is formed with a female screw portion that is screwed with a male screw portion of the linear motion rod.

According to the present invention, in a seal structure or the like in a linear motion system, assembly is easy and the sealing performance can be improved.

It is a figure which shows the assembly state of the seal structure which concerns on 1st embodiment of this invention. It is a front view of (A) a linear motion rod of a seal structure concerning a first embodiment of the present invention, and (B) is a bottom view of a linear motion rod. It is a front sectional view of (A) a washer of a seal structure concerning a first embodiment of the present invention, (B) a bottom view of a washer, (C) a top view of a piston member, and (D) a front view of a piston member. It is a figure which shows the state in the middle of the assembly of the seal structure which concerns on 1st embodiment of this invention. (A) is the fastening state figure of the piston member and washer of the Piceal structure concerning a first embodiment of the present invention, and (B) thru / or (D) are the figures showing the modification. (A) thru | or (C) are the fastening state figures of the piston member and washer of the seal structure which concern on the modification of 1st embodiment of this invention. (A) thru | or (D) are the front views and bottom views of a linear motion rod of the seal structure which concern on the modification of 1st embodiment of this invention. It is a figure which shows the assembly state of the seal structure which concerns on the modification of 1st embodiment of this invention. It is an assembly state figure of the seal structure concerning a second embodiment of the present invention. It is the front view and bottom view of (A) linear motion rod used for the seal structure which concerns on 2nd embodiment of this invention, (B) The bottom view of a washer. It is the side view and bottom view of (A) a linear motion rod used for the seal structure which concerns on the modification of 2nd embodiment of this invention, (B) The bottom view of a washer. (A) (B) is an exploded view of the seal structure which concerns on the modification of 2nd embodiment of this invention. It is (A) assembly state figure and (B) exploded view of the seal structure which concerns on the modification of 1st embodiment of this invention. It is (A) assembly state figure and (B) exploded view of the seal structure which concerns on the modification of 2nd embodiment of this invention. It is (A) assembly state figure and (B) exploded view of the seal structure which concerns on the modification of 2nd embodiment of this invention. It is (A) assembly state figure and (B) exploded view of the seal structure which concerns on the modification of 2nd embodiment of this invention. It is a fragmentary sectional view showing a seal structure concerning a third embodiment of the present invention. It is (A) sectional drawing, (B) front view, and (C) bottom view which show the internal thread body used with the seal structure which concerns on 3rd embodiment of this invention. (A) And (B) is the front view and bottom view which show the modification of the linear motion rod used with the seal structure which concerns on embodiment of this invention. (A) And (B) is a fragmentary sectional view showing the modification of the seal structure concerning the embodiment of the present invention. It is a fragmentary sectional view showing the modification of the seal structure concerning the embodiment of the present invention. (A) And (B) is a fragmentary sectional view showing the modification of the seal structure concerning the embodiment of the present invention. (A) It is a top view of the seal structure which concerns on 4th embodiment of this invention. (B) It is a front view of an assembly structure. FIG. 24 is a sectional view taken along line AA in FIG. It is the figure which expanded and showed the external thread part of the linear motion rod. (A) to (d) are views showing relative operations of a piston member and a fixing female screw body. It is a front fragmentary sectional view which shows a relative rotation prevention mechanism. It is the front fragmentary sectional view and bottom view of the external thread body for engagement used with a relative rotation prevention mechanism. It is the top view and front fragmentary sectional view of a washer used with a relative rotation prevention mechanism. (A) is a conceptual diagram showing the action of the saw blade of the relative rotation preventing mechanism, and (B) to (D) are conceptual diagrams showing modified examples of the saw blade. (A)-(C) are conceptual diagrams showing modifications of the saw blade of the relative rotation preventing mechanism. (A) (B) is the top view and front fragmentary sectional view of a washer used by the application example of a relative rotation prevention mechanism. It is the top view and front fragmentary sectional view which show the relative rotation prevention mechanism of the seal structure which concerns on 5th embodiment. (A) is the top view and front fragmentary sectional view of the washer used with the relative rotation prevention mechanism, (B) is the front fragmentary sectional view which shows the open | release operation | work of the relative rotation prevention mechanism. (A) is a front fragmentary sectional view showing a washer opening operation used in an application example of the relative rotation prevention mechanism, and (B) is a plan view and a front partial sectional view showing a washer opening operation used in the application example. FIG. (A) Top view and front partial cross-sectional view of washer of relative rotation prevention mechanism of seal structure according to sixth embodiment, (B) Front partial cross-sectional view showing a state where washer and engaging male screw body are integrated, ( C) is a front partial sectional view showing a fastening state. (A) thru | or (C) are the top views which show the application example of the same relative rotation prevention mechanism, (D) is the top view and front fragmentary sectional view of the washer used by another application example. (A) The top view and front fragmentary sectional view of a washer of the relative rotation prevention mechanism of the seal structure which concern on 7th embodiment, (B) The front fragmentary sectional view which shows a fastening state. It is (A) top view and (B) front sectional view concerning an example of application of the seal structure. It is front sectional drawing of the (A) fastening state of the seal structure which concerns on 8th embodiment, (B) Front sectional drawing which shows the cancellation | release state of a relative rotation prevention mechanism. It is front sectional drawing of the seal structure used as the application example of 4th to 8th embodiment. It is front sectional drawing of the seal structure used as the other application example of 4th to 8th embodiment. It is front sectional drawing which expands and shows the external thread part of the linear motion rod of the seal structure used as the other application example of 4th to 8th embodiment. It is front sectional drawing of the seal structure used as the other application example of 4th to 8th embodiment. It is front sectional drawing of the seal structure of 9th embodiment. It is front sectional drawing which shows the application example of the seal structure of 9th embodiment. It is sectional drawing which shows the basic composition of the hydraulic piston which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. First, a basic structure of a hydraulic piston as an example of a linear motion system to which the seal structure 1 of the present invention can be applied will be described with reference to FIG. The hydraulic piston includes a piston body 300 that functions as a piston, a linear motion rod 10 that functions as a piston rod, a tube 4, a rod cover 5, and a head cover 6. The piston body 300 is composed of, for example, a plurality of members, is fixed to the linear motion rod 10, and is disposed in the cylindrical tube 4. In the tube 4, a ring-shaped rod cover 5 is disposed on the side from which the linear rod 10 protrudes, and a head cover 6 is disposed on the opposite side. Therefore, both ends of the tube 4 are covered with the rod cover 5 and the head cover 6 so that a pressure space is formed inside. Further, near the both ends of the tube 4 are formed

openings

7 and 8 through which the working fluid is taken in and out of the tube 4. Oil flows into the pressure space through the

openings

7 and 8, and the piston body 300 moves. It has a structure to let you.

FIG. 1 shows the seal structure of the linear motion system according to the first embodiment. The seal structure includes a linear motion rod 10, an annular washer 50 serving as a cooperation member, and a piston member 100. A piston ring (outer seal member) 90 is provided around the piston member 100. A piston body 300 is configured by the washer 50, the piston member 100, the piston ring 90, and the like. Here, various members into which the linear rod 10 is inserted are also expressed as “members to be inserted”, and these constitute a part of the piston body 300. Therefore, the washer 50 and the piston member 100 are inserted members.

The piston member 100 is a cylindrical member, and has an annular outer peripheral surface 105 facing the inner peripheral surface of the tube 4, a pair of end surfaces 101 facing in the axial direction, and an insertion formed coaxially with the outer peripheral surface. It has a hole 100a. The outer peripheral surface 105 is close to the inner peripheral surface of the tube 4 and serves as a seal portion 105a that restricts the movement of the working fluid. At least one of the end surfaces 101 serves as a pressure receiving surface 101a that receives the pressure of the working fluid. The linear motion rod 10 is inserted into the insertion hole 100a.

Further, on the outer peripheral surface 105 of the piston member 100, an annular outer seal fitting portion 210 that continues from the middle to the end surface 101 on the washer 50 side is formed. The outer seal fitting portion 210 forms a small-diameter surface 201 that continues to the end surface 101 on the washer 50 side on the peripheral surface, and the piston ring 90 is inserted into the small-diameter surface 201 and is in contact with and fitted therein. The small diameter surface 201 is smaller in diameter than the outer peripheral surface (seal portion 105a) of the piston member 100, and the piston ring 90 is positioned in the axial direction by the step 205 formed on the seal portion 105a and the small diameter surface 201. The axial dimension of the piston ring 90 is set to be slightly larger than the axial dimension of the small diameter surface 201, and the piston ring 90 slightly protrudes from the piston member 100 toward the washer 50. The washer 50 is set to have a diameter larger than that of the small diameter surface 201. Therefore, when the washer 50 and the piston member 100 are fastened, the end face of the washer 50 comes into contact with the piston ring 90 and the piston ring 90 is fixed. That is, the piston ring 90 is sandwiched between the piston member 100 and the washer 50. The washer 50 is disposed in the vicinity of the end surface of the piston member 100 and functions as an outer seal holding member that presses the piston ring 90 toward the outer seal fitting portion 210 side.

As a result of the above, it is possible to easily assemble the piston ring 90 as compared with the conventional case where the sealing member is fitted and installed while being elastically deformed. Accordingly, since it is not necessary to consider the elastic deformation of the piston ring 90, it is possible to freely select a material having high rigidity and high wear resistance.

As shown in FIG. 2A, the linear motion rod 10 has a main body 12a and an end 12c in the shaft portion 12. A step portion 20 is formed at the boundary between the main body portion 12a and the end portion 12c, and a rod side seat portion 22 is formed at a portion corresponding to a lower portion or a root of the step portion 20. The main body 12a has a cylindrical shape. A male screw portion 13 is formed at the end portion 12c.

As shown in FIG. 2 (B), a rod-side cooperation region 17 having a non-circular cross section when viewed from the axial direction is formed at the end 12c. Here, the rod side cooperation area | region 17 is formed in the base end side rather than the external thread part 13 in the edge part 12c. Specifically, the rod-side cooperation region 17 has a shape in which a part of a circular arc with a circular cross section is omitted along the chord (which is an irregular shape). Become. As a result, the rod-side contact portion 23 becomes a plane that is perpendicular to the radial direction and directed outward in the radial direction on the peripheral surface of the end portion 12c. The rod-side contact portion 23 has a distance from the axial center of the screw that fluctuates along the circumferential direction, and the first rod-side contact region 23Y has a distance X1 along one circumferential direction X of the linear motion rod 10. X2 increases. In the second rod side contact region 23X, the distances Y1 and Y2 increase along the other circumferential direction Y of the linear motion rod 10. Note that this amount of variation is set to be the same as that of a washer-side contact portion 53 described later if a slight margin is ignored. Alternatively, the margin gap may be set so as to be filled by deformation in the direction perpendicular to the axis caused by axial compression caused by tightening of the washer 50 by the piston member 100.

Further, the minimum radius 17Y from the axis of the rod side cooperation region 17 is set to be equal to or greater than the maximum radius 13X from the axis of the male screw portion 13. Therefore, it is preferable that the maximum radius 17Y from the axis of the rod side cooperation region 17 is set larger than the maximum radius 13X from the axis of the male screw portion 13.

As shown in FIGS. 3A and 3B, a first receiving portion 60 is formed on one surface of the washer 50. The first receiving portion 60 faces the seat portion 102 of the piston member 100, and a first relative rotation preventing mechanism A is formed between the two. In the first relative rotation preventing mechanism A, when at least the piston member 100 tries to rotate in a loosening direction with respect to the linearly acting rod 10 to be screwed, the first receiving portion 60 and the seat portion 102 of the piston member 100 are mutually connected. Engagement prevents relative rotation between the first receiving portion 60 and the rod side seat portion 22 with respect to the rotation direction. A second receiving portion 70 is formed on the other side of the washer 50. The second receiving portion 70 faces the step portion 20 of the linear motion rod 10.

The piston rod insertion hole 52 in the washer 50 is non-circular when viewed from the axial direction. The insertion hole 52 has a shape in which a part of the circular arc is omitted along the string, and engages with the rod-side cooperation region 17 of the linear motion rod 10 in the circumferential direction (this washer). The cross-sectional non-circular region in the 50 insertion holes 52 is defined as “piston side cooperation region”, and the engagement structure between the piston side cooperation region and the rod side cooperation region 17 is defined as “auxiliary relative rotation prevention mechanism B”) .

Specifically, the auxiliary relative rotation prevention mechanism B includes a washer side contact portion 53 formed in the insertion hole 52 of the washer 50 and a rod side contact portion formed in the rod side cooperation region 17 of the linear motion rod 10. 23. As described above, the insertion hole 52 of the washer 50 has a partial arc shape that is concentric with respect to the axis of the screw, and the remaining portion is cut into a straight line like a string. The string becomes the washer side contact portion 53. Accordingly, the inner wall of the insertion hole 52 of the washer 50 has a planar shape in a portion corresponding to the washer-side contact portion 53, and the distance from the screw shaft center varies along the circumferential direction. Specifically, in the first washer side contact region 53X, the distances XA and XB increase along one circumferential direction X of the washer 50. In the second washer side contact region 53Y, the distances YA and YB increase along the other circumferential direction Y of the washer 50. The portion excluding the washer-side contact portion 53 has a perfect circular shape with a constant distance from the screw shaft center. Further, the minimum radius 52Y from the axis of the insertion hole 52 is set to be equal to or larger than the maximum radius 13X of the male screw portion 13. As a result, the insertion hole 52 and the external thread portion 13 of the linear motion rod 10 do not need to interfere with each other.

Therefore, when the end 12c of the linear motion rod 10 is inserted into the insertion hole 52 of the washer 50, the washer-side contact portion 53 and the rod-side contact portion 23 come into contact with each other, and the screw shafts are aligned. Their relative rotation in the circumferential direction is restricted. That is, the washer-side contact portion 53 and the rod-side contact portion 23 act as the auxiliary relative rotation prevention mechanism B.

Further, as the first relative rotation preventing mechanism A, the first receiving portion side unevenness 64 that engages with the piston side unevenness 104 is formed in the first receiving portion 60 of the washer 50. The 1st receiving part side unevenness | corrugation 64 becomes the saw blade shape provided in multiple numbers by the circumferential direction continuously. The direction in which each of the first receiving portion side irregularities 64 extends, that is, the direction in which the ridge line extends, is along the radial direction of the washer 50. As a result, the first receiving portion side unevenness 64 extends radially from the center of the through hole 52 of the washer 50.

Further, the first receiving portion 60 is formed with a washer side tapered surface inclined in the radial direction. The washer-side taper surface is inclined so that the center side approaches the stepped portion 20 side of the linear motion rod 10 (see FIG. 1), resulting in a concave conical shape. The first receiving portion side irregularities 64 described above are formed on the washer side tapered surface.

3 (C) and 3 (D), the insertion hole 100a of the piston member 100 is formed with a female thread portion 106a for screwing with the linear motion rod 10. Further, the piston member 100 is formed with a seat portion 102 that faces the first receiving portion 60 of the washer 50. Both the seat portion 102 and the first receiving portion 60 on the washer 50 side are annular surface regions, and abut against each other to play a role of transmitting a fastening force (axial force) to the step portion 20. That is, most of the axial force in this fastening structure is transmitted to the step portion 20 via the washer 50. Further, the piston ring 90 is held by the piston member 100 and the washer 50 by this axial force.

As shown in FIG. 3, as the first relative rotation preventing mechanism A, the female screw side unevenness 104 is formed in the seat portion 102 of the piston member 100. The female screw side unevenness 104 has a saw blade shape that is continuously provided in the circumferential direction. The direction in which each of the female screw side irregularities 104 extends, that is, the direction in which the ridge line extends is the radial direction of the piston member 100. As a result, the female screw side unevenness 104 extends radially from the axis.

Furthermore, the female thread side taper surface which inclines in the radial direction is formed in the seat portion 102. Since the female thread side taper surface is inclined so that the center side approaches the washer 50 side, as a result, a convex conical shape is formed on the stepped portion 20 side of the linear motion rod 10. The female screw side unevenness 104 described above is formed on the female screw side tapered surface.

As described above, as the first relative rotation preventing mechanism A, since the female screw side unevenness 104 and the first receiving portion side unevenness 64 are formed in a saw blade shape that is continuous in the circumferential direction, a so-called ratchet mechanism or one-way clutch mechanism is provided. Works. As a result, during the fastening operation of the piston member 100, the relative movement of the female screw side unevenness 104 and the first receiving portion side unevenness 64 of the washer 50 is allowed to realize smooth relative rotation. On the other hand, during the loosening operation of the piston member 100, the relative movement of the female screw side unevenness 104 and the first receiving portion side unevenness 64 of the washer 50 is completely restricted. As a result, workability at the time of fastening and subsequent locking can be rationally achieved.

Further, as the first relative rotation preventing mechanism A, the seat portion 102 and the first receiving portion 60 are formed with the piston-side tapered surface and the washer-side tapered surface, so that the contact area between both can be increased. Further, the fastening force in the axial direction by this fastening structure also acts in the radial direction by the tapered surface. By pressing the taper surfaces of each other in the radial direction, centering can be carried out by self-excitation. As a result, the concentricity between the piston member 100 and the washer 50 is increased, and the engagement accuracy between the female screw side unevenness 104 and the first receiving portion side unevenness 64 can be increased. It is also preferable to slightly increase the inclination of the convex female thread side taper surface and slightly decrease the inclination angle of the concave washer side taper surface so as to provide a small difference in angle. If it does in this way, a mutual taper surface can be made to contact | abut little by little toward the radial direction outer side from the center with the increase in clamping pressure.

Further, the auxiliary relative rotation prevention mechanism B avoids the shapes of the washer side contact portion 53 and the rod side contact portion 23 from being concentric and circular with respect to the screw shaft center. In other words, the shapes of the washer-side contact portion 53 and the rod-side contact portion 23 vary along the circumferential direction in the distance from the screw axis. Due to this non-circular shape, once the washer-side contact portion 53 and the rod-side contact portion 23 are in contact with each other, further relative rotation in the circumferential direction is restricted as long as the axes are aligned. In particular, the washer side abutting portion 53 and the rod side abutting portion 23 are not formed over the entire circumference of the linear motion rod 10, but are formed partially in the circumferential direction. These shape processing of the rod 10 can be, for example, simple chamfering processing or press processing.

As shown in FIG. 4, when the washer 50 is inserted into the linear motion rod 10 and the piston member 100 is further tightened, the linear motion rod 10 and the washer 50 are first engaged in the circumferential direction by the auxiliary relative rotation prevention mechanism B. Further, when the piston member 100 is further tightened, in the first relative rotation prevention mechanism A, the female screw side tapered surface of the seat portion 102 enters the recess of the washer side tapered surface of the washer 50, and the female screw side unevenness 104 and the first receiving portion are formed. The side unevenness 64 is engaged and the state shown in FIG. 1 is obtained. As shown in FIG. 5 (A), both sawtooth shapes in the first relative rotation preventing mechanism A are such that when the piston member 100 tries to rotate in the fastening direction Y, the

inclined surfaces

104Y and 64Y contact each other. The relative slide is allowed while the distance between the two is reduced in the axial direction. On the other hand, when the piston member 100 tries to rotate in the loosening direction X, the mutually perpendicular surfaces (surfaces with a strong inclination) 104X and 64X come into contact with each other to prevent the relative movement between them. In particular, the first relative rotation preventing mechanism A is engaged with the female screw side unevenness 104 and the first receiving portion side unevenness 64 as the distance between the female screw side seat portion 102 and the first receiving portion 60 decreases by tightening the piston member 100. It becomes stronger and the engagement strength on the loosening direction X side is increased. Here, the inclination angle of the female thread side taper surface and the inclination angle of the washer side taper surface are made different from each other. In particular, the inclination angle from the axis of the washer side taper surface is set to the inclination angle from the axis of the female screw side taper surface. By setting the width narrower than that, it is possible to tighten without play regardless of the pitch of the sawtooth formed on each tapered surface.

As described above, according to the seal structure of the first embodiment, since the outer seal fitting portion 210 is formed on the piston member 100, the piston ring 90 can be easily assembled. Accordingly, since it is not necessary to consider the elastic deformation of the piston ring 90, it is possible to select a material having high rigidity and high wear resistance. Further, since the piston ring 90 can be held in the axial direction by the washer 50 and the piston member 100, the piston ring 90 can be prevented from falling off.

Further, by interposing the washer 50, the first relative rotation prevention mechanism A is formed between the female thread side seat portion 102 of the piston member 100 and the first receiving portion 60 of the washer 50, while the insertion hole 52 of the washer 50 is An auxiliary relative rotation prevention mechanism B is configured between the rod side cooperation regions 17 of the linear motion rod 10. As a result, when the piston member 100 or the linear motion rod 10 tries to relatively rotate in the loosening direction, both the linear motion rod 10 and the linear motion rod 10 are caused by the circumferential engagement action of both the first relative rotation prevention mechanism A and the auxiliary relative rotation prevention mechanism B. The relative rotation of the piston member 100 is restricted, and reverse rotation, that is, loosening is prevented. Therefore, even if vibration etc. arise, the fastening state which does not loosen at all can be obtained. On the other hand, when the linear motion rod 10 and the piston member 100 are relatively rotated in the tightening direction, the one-way clutch structure of the first relative rotation prevention mechanism A allows the relative rotation of the washer 50 and the piston member 100. It is possible to do freely.

Further, since the piston member 100 is not loosened by the mechanical structure of the first relative rotation prevention mechanism A and the auxiliary relative rotation prevention mechanism B, it is not necessary to retighten the piston member 100 more than necessary. An appropriate clamping force can be applied to the piston ring 90.

In the first embodiment, as the first relative rotation preventing mechanism A, the case where the female screw side unevenness 104 and the first receiving portion side unevenness 64 are saw-tooth shaped is illustrated, but the present invention is not limited to this. For example, as shown in FIG. 5B, the unevenness of each other can be formed in a mountain shape (both are inclined surfaces). In this way, when the piston member 100 rotates in the loosening direction X, the

inclined surfaces

104X and 64X tend to move relative to each other, and the female screw side unevenness 104 and the first receiving portion side unevenness are along this inclined surface. 64 tries to leave. If the moving distance (the angle α to be separated) is set larger than the lead angle of the piston member 100, the female screw side unevenness 104 and the first receiving portion side unevenness 64 may be further separated even if the piston member 100 tries to loosen. You will not be able to relax. 5B illustrates the isosceles triangle asperity in cross section. However, as shown in FIG. 5C, the slopes of the

inclined surfaces

104Y and 64Y that are in contact with each other at the time of fastening rotation are smaller than those at the time of loose rotation. It is also preferable to make the inclination angles of the

inclined surfaces

104X and 64X in contact with each other gentle. In this manner, the circumferential distance P between the

inclined surfaces

104Y and 64Y that must be overcome during the fastening rotation can be shortened, so that the backlash (gap) after fastening can be reduced.

Further, as an application of FIGS. 5 (A) to 5 (C), as shown in FIG. 5 (D), corrugated irregularities with curved ridges and valleys are also preferable, and smooth operability can be obtained at the time of fastening. it can. Furthermore, in the first embodiment, the unevenness extending in the radial direction is exemplified, but it is also preferable to form a spiral (spiral) groove or mountain (unevenness) as shown in FIG. In addition, as shown in FIG. 6B, even a groove or mountain (unevenness) extending linearly can be inclined so that the circumferential phase changes with respect to the radial direction of the screw. Moreover, as shown in FIG. 6C, it is also preferable to adopt a so-called embossed shape in which a plurality of fine irregularities are formed both in the circumferential direction and the radial direction (planar shape) of the screw.

Further, as in the first embodiment, it is not always necessary to make the concave and convex shapes of the female screw side irregularities 104 and the first receiving portion side irregularities 64 coincide (similar). For example, different shapes from the various shapes in FIGS. 5 and 6 can be selected and combined with each other.

In the first embodiment, the case where the female thread side tapered surface is convex and the washer side tapered surface is concave is illustrated, but the present invention is not limited to this, for example, the female thread side tapered surface is concave and washer. The side taper surface can be convex. On the other hand, both of them can be non-tapered surfaces perpendicular to the screw axis. Further, for example, if the elastic deformation of the washer 50 is effectively used, it is not necessary to match the inclination angles of the two tapered surfaces. Of course, only one of the piston member 100 or the washer 50 may be formed with a tapered surface. Furthermore, by making both the tapered surfaces convex or concave, the elastic deformation of the washer can be utilized to bring them into close contact. Further, in order to obtain the elasticity of the washer 50, the basic shape of the washer 50 is preferably a so-called spring washer shape or a disc spring shape in which a spiral shape is used.

Moreover, although the linearly acting rod 10 of this first embodiment illustrated the case where a groove | channel (constriction) was provided in the boundary of the rod side cooperation area | region 35 and the external thread part 13 in detail in the middle of the edge part 12c, this invention is shown. It is not limited to this. A structure in which the rod-side cooperation region 35 and the male screw portion 13 are continuous without a groove is also preferable, and the strength of the linear rod 10 can be increased. Moreover, although the case where the step part 20 was formed in the boundary of the main-body part 12a and the edge part 12c was shown, this invention is not limited to this, It is made to make the main-body part 12a and the edge part 12c continue with the same diameter. Good.

Furthermore, as an application of the auxiliary relative rotation prevention mechanism B of the first embodiment, as shown in FIG. 7A, as the rod-side cooperation region 17 of the linear motion rod 10, a plurality of locations around the end portion 12c (here, You may form rod side contact part 23A in 2 places. As shown in FIG. 7B, a projection 23B that protrudes radially outward from the periphery of the end 12c may be formed as the rod-side cooperation region 17 of the linear motion rod 10. As shown in FIG. 7C, the end 12c may be a polygonal section 23C (here, a hexagon) as the rod-side cooperation region 17 of the linear motion rod 10. Further, as shown in FIG. 7D, the end 12c may be formed into an elliptical cross section 23D as the rod-side cooperation region 17 of the linear motion rod 10. All of them have a “non-circular cross section” shape. At this time, although not particularly shown, it is preferable that the insertion hole 52 of the washer 50 has a similar shape corresponding to these, but it is necessary to make both the shapes similar if they can be engaged in the circumferential direction. Absent.

In the case of this structure, as shown in FIG. 8 (A), a convex taper surface 11 is formed on the linear motion rod 10, and a taper surface 51 is formed on a washer 50 serving as an inserted member. Is preferably brought into contact. As a result, by tightening the washer 50 with the piston member 100 and pressing the

tapered surfaces

11 and 51 together, the axes of the washer 50 and the linear rod 10 can be made to coincide with each other with high accuracy. In addition, the inner seal member 82 is interposed between the taper surfaces 11 and 51 and the taper surface 11 is brought into contact with the inner seal member 82, thereby suppressing oil leakage.

In this structure, the radius sizes of the cooperating member (washer) 50 and the piston member 100 are substantially the same, and the piston ring 90 is accommodated in the outer seal fitting portion 210 on the piston member 100 side and sandwiched by the washer 50. ing. Therefore, as shown in FIG. 8B, it is also possible to form an outer seal fitting portion 210 on the washer 50 side, accommodate the piston ring 90 therein, and sandwich the piston ring 90 between them. In this case, it is possible to define the washer 50 as an inserted member as a piston, and define the piston 100 as an inserted member as a female screw body for preventing the washer 50 from falling off. In the following description, it is first described that the second embodiment and thereafter can also be used in which the linkage member (washer) also serves as a piston, or the definitions of the washer and the piston can be appropriately reversed.

Next, the seal structure according to the second embodiment will be described with reference to FIGS. In addition, description is abbreviate | omitted about the structure or member similar or similar to 1st embodiment.

As shown in FIG. 10 (A), the rod-side cooperation region 17 is formed on the linear motion rod 10 so as to overlap the male screw portion 13. The rod-side cooperation region 17 is such that, when viewed from the axial direction, a part of a circular arc having a right circular cross section formed along the apex of the thread is omitted (or cut) along the chord. The shape of the string is the rod side contact portion 23. That is, a part of the screw thread is omitted so as to be continuous in the axial direction, thereby forming a virtual plane P that is perpendicular to the radial direction and directed outward in the radial direction. It becomes. Accordingly, the minimum radius 17Y of the rod side cooperation region 17 is set to be smaller than the maximum radius 13X of the male screw portion 13.

Further, in the present embodiment, the thread bottom 13a remains around the rod side contact portion 23 in the axial direction. As a result, the function of screwing with the piston member 100 remains. Specifically, in the rod side contact portion 23, it is preferable to omit the upper limit of two-thirds of the thread height, and more preferably, omit the upper limit of one-half of the thread height. To do. Therefore, the minimum radius (minimum distance) 17Y of the rod side cooperation region 17 is larger than the minimum radius (valley bottom radius) 13Y from the axis of the male screw portion 13. In the present embodiment, the rod-side contact portions 23 are formed at three locations that have a phase difference of 23 degrees in the circumferential direction.

As shown in FIG. 10 (B), the insertion hole 52 through which the piston rod of the washer 50 can be inserted is a piston-side cooperation region that is non-circular when viewed from the axial direction. The insertion hole 52 has a partial arc shape concentric with the axis of the screw and has a shape in which the remaining portion is cut off linearly like a string. 53. In the present embodiment, the washer-side contact portions 53 are formed in three places that have a phase difference of 120 degrees in the circumferential direction. The washer side abutting portion 53 abuts on the rod side abutting portion 23 of the rod side cooperation region 17 so as to engage with each other in the circumferential direction to constitute the auxiliary relative rotation preventing mechanism B.

Furthermore, in this embodiment, the outer

seal fitting portions

56 and 210 are formed on the outer peripheral surface of the washer 50 and the outer peripheral surface of the piston member 100 so as to face each other. Accordingly, the piston ring 90 is accommodated in the pair of outer

seal fitting portions

56 and 210.

As described above, in the seal structure of the second embodiment, as shown in FIG. 9, the gap between the insertion hole 52 of the washer 50 and the rod-side cooperation region 17 formed to overlap with the male thread portion 13 of the linear motion rod 10. The auxiliary relative rotation prevention mechanism B can be configured. Accordingly, the engagement position with the washer 50 can be freely changed within the range where the rod-side cooperation region 17 exists, so that the piston 10 and the piston ring 90 can be fixed only by changing the axial dimension of the washer 50. The position can be adjusted. Note that a sleeve may be interposed between the washer 50 and the step portion 20 of the linear rod 10, and in that case, the fixed value position of the piston 10 can be adjusted only by changing the axial dimension of the sleeve. Furthermore, here, since the bottom of the thread is left as much as possible in the rod side contact portion 23 of the rod side cooperation region 17, a decrease in the fastening force with the piston member 100 hardly occurs. Yes.

In addition, although the linear motion rod 10 of this 2nd embodiment illustrated the case where the rod side cooperation area | region 17 was not provided in the main-body part 12a, making the cross-sectional shape of the main-body part 12a substantially correspond with the rod side cooperation area | region 17. Thus, it is possible to extend the rod side cooperation region 17 to the main body portion 12a. Of course, the main body 12a itself can be eliminated.

FIG. 11 shows another modification of the second embodiment. As shown in FIG. 11 (A), in the rod side cooperation region 17 formed to overlap with the male screw portion 13, when viewed from the axial direction, the rod side contact portion 23 in which the top of the thread is omitted in a concave shape is formed. It is formed. More specifically, the rod-side abutting portion 23 is configured such that the top of the thread is recessed in a V shape, and is formed at twelve locations in the circumferential direction at equal intervals. A minimum distance (bottom portion of the dent) 17Y from the axis of the rod side contact portion 23 is set to be smaller than the maximum radius 13X of the male screw portion 13 and larger than the minimum radius (valley bottom radius) 30bY of the male screw portion 13. The

Therefore, as shown in FIG. 11 (B), the insertion hole 52 of the washer 50 assembled to the linear motion rod 10 also has a washer side that is convex inward in the radial direction so as to be similar to the rod side cooperation region 17. The contact parts 53 are formed at twelve places in the circumferential direction at equal intervals. As a result, the washer 50 and the linear rod 10 can be engaged in the circumferential direction.

In the second embodiment, the minimum distance 17Y from the axis of the rod-side contact portion 23 in the rod-side cooperation region 17 formed in the male screw portion 13 is smaller than the minimum radius (valley bottom radius) 30bY of the male screw portion 13. Although the case where it is set large is illustrated, the present invention is not limited to this. For example, as shown in FIG. 12A, an axial groove deeper than the bottom of the thread can be formed in the male screw portion 13, and this can be used as the rod-side contact portion 23. As a result, the minimum distance 17Y from the axis of the rod-side contact portion 23 is smaller than the minimum radius (valley bottom radius) of the male screw portion 13. In this case, the result is that the thread of the male thread portion 13 is partially omitted including the valley bottom. A washer-side contact portion 53 that protrudes inward in the radial direction is also formed in the insertion hole 52 of the washer 50, and the minimum distance from the axial center is the minimum radius (valley bottom radius, that is, the valley diameter) of the male screw portion 13. Make it smaller. As a result, it is possible to increase the circumferential engagement dimension between the washer-side contact portion 53 and the rod-side contact portion 23.

In the first and second embodiments, the case where the washer 50 and the piston member 100 are formed with inclined surfaces (tapered surfaces) and brought into contact with each other is illustrated, but the present invention is not limited to this. As shown in FIG. 12B, a cylindrical surface is formed on both the washer 50 and the piston member 100, a first receiving portion side unevenness 64 is formed on the cylindrical surface of the washer 50, and a female screw is formed on the cylindrical surface of the piston member 100. By forming the side irregularities 104, they may be engaged with each other in the circumferential direction.

In the first and second embodiments, the case where the linear motion rod 10 has the stepped portion 20 is illustrated, but the present invention is not limited to this. For example, as an application of the first embodiment, as shown in FIG. 13, it is possible to fasten the cooperative member (washer) 50 so as to be sandwiched between the pair of

piston members

100, 100 from both sides. At this time, a pair of receiving portions 60 serving as the first relative rotation preventing mechanism A is formed on both sides of the linkage member 50, and the receiving

portions

60 and 60 are engaged with the seat portion 102 of the piston member 100. In this way, the

piston members

100, 100 arranged on both sides are prevented from rotating relative to the linear motion rod 10 in the loosening direction due to the presence of the receiving

portions

60, 60 formed on the cooperation member 50. The

In this case, the outer

seal fitting portions

210 and 210 are formed on each of the pair of

piston members

100 and 100, and the outer

seal fitting portions

56 and 56 are also formed on both ends of the cooperation member (washer) 50. be able to. Accordingly, the two

piston rings

90 and 90 can be held at the boundary between the pair of

piston members

100 and 100 and the linkage member (washer) 50.

Further, as an application of the second embodiment, it is possible to fasten a cooperative member (washer) 50 as shown in FIG. 14 so as to be sandwiched between the pair of

piston members

100 and 100 from both sides. In the linear motion rod 10, the stepped portion 20 is omitted, and a male screw portion 13 is formed therein, and a rod side cooperation region 17 is formed so as to overlap with the male screw portion 13. A pair of receiving portions 60 serving as the first relative rotation preventing mechanism A is formed on both sides of the linkage member 50, and the receiving

portions

piston members

portions

60, 60 formed on the cooperation member 50. The

13 and 14 realizes that the pair of

piston members

100, 100 are fixed at an arbitrary position on the linear motion rod, but only one of the pair of piston members is substantially used. The piston 100 may function, and the other may function as a female screw body. Further, the cooperation member 50 can also serve as a part of the piston. Specifically, as shown in FIG. 15, a piston member 100A that also serves as a female screw body is fastened from one side to a cooperative member (washer) 50 having receiving

portions

60, 60 on both sides, and a female screw body is provided from the other side. If 100B is fastened, the three members of the piston member 100A, the linkage member 50, and the female screw body 100B can be fixed at an arbitrary place. Here, the outer seal fitting portion 210 is formed only on the piston member 100A side, and one piston ring 90 is disposed there.

Further, as in the structure of FIG. 16 which is a modification of the seal structure of the linear motion system of FIG. 15, an arm that wraps around the polygonal circumferential surface of the female screw body 100 </ b> B or a plane opposite to the seat 102 in the washer 50. It is also preferable to form the relative rotation preventing mechanism A by forming the arm 58 and engaging the arm 58 and the female screw body 100B in the circumferential direction.

Next, the seal structure of the third embodiment will be described with reference to FIGS. In addition, this 3rd embodiment becomes an application of the seal structure shown in FIG. 11 of 2nd embodiment, and abbreviate | omits description about the same or similar member. This seal structure is characterized in that the function of the washer (cooperating member) 50 is provided integrally with the piston member 100 so that the independent washer (cooperating member) 50 can be omitted.

As shown in FIG. 18, the piston member 100 has a piston-side cooperation region 106 b having a non-circular cross section when viewed from the axial direction in the insertion hole 100 a having a female screw portion 106 a screwed with the male screw portion 13. The piston-side cooperation region 106b is provided on the opposite side of the seat portion 102 of the piston member 100 so as to protrude in a ring shape in the axial direction, but may be provided on the seat portion 102 side and overlaps with the female screw portion 106a. You may form as follows.

In the piston-side cooperation region 106b, female screw-side contact portions 108 that are convex inward in the radial direction are formed at equal intervals in the circumferential direction on the inner peripheral surface of the insertion hole 100a. As a result, the female screw side contact portion 108 can be engaged in the circumferential direction with the rod side contact portion 23 formed to be recessed in the male screw portion 13 of the linear motion rod 10. As already described, the female thread side abutting portion 108 protrudes in the axial direction on the opposite side of the seat portion 102 of the piston member 100 and is thinly provided so that it can be elastically deformed radially outward. By causing the linearly acting rod 10 and the piston member 100 to rotate relative to each other with a desired force, the piston-side contact portion 108 is elastically deformed outward, and the circumferential engagement with the rod-side contact portion 23 is released. Can do.

Therefore, as shown in FIG. 17, a positioning sleeve 18 (also defined as an inserted member) is disposed between the step portion 20 of the linear rod 10 and the piston member 100, and the linear rod 10 If the piston member 100 is biased in a direction to be tightened with a desired force, the rod-side contact portion 23 and the female screw contact portion 108 can be allowed to rotate relative to each other while being repeatedly engaged and released. Can be fixed in the middle of the male thread. More desirably, as a so-called ratchet mechanism in which at least one of the rod-side contact portion 23 and the female screw-side contact portion 108 has a saw blade shape, rotation in the tightening direction is allowed and rotation in the loosening direction is restricted. Make it work.

Further, the insertion hole of the sleeve 18 has a basic hole 18A into which the linear rod 10 is inserted, and an annular inner seal housing that is larger in diameter than the basic hole 18A and continues to the end surface of the linear rod 10 on the main body side. It has a hole 18B. A step portion 18C is formed between the inner seal accommodation hole 18B and the basic hole 18A. An annular inner seal member 82 is accommodated in the inner seal accommodation hole 18B, and engages with the step portion 18C in the axial direction. Therefore, by tightening the piston member 100, the inner seal member 82 is pressed against the step portion 21 of the linear rod 19 via the sleeve 18, and the working fluid is sealed. Here, an accommodation recess 18 </ b> D is formed on the outer peripheral surface of the sleeve 18, and the auxiliary seal member 83 is accommodated therein to seal between the piston member 100 and the sleeve 18. Note that the piston member 100 and the sleeve 18 may be formed integrally, and in this case, the auxiliary seal 83 can be omitted.

In the first to third embodiments, the case where the rod-side contact portion 23 of the rod-side cooperation region 17 extends linearly in the axial direction is mainly exemplified, but the present invention is not limited to this. For example, as shown in FIGS. 19A and 19B, it is also preferable that the rod-side contact portion 23 is formed to be spirally inclined with respect to the axial direction. At this time, the spiral direction of the rod side contact portion 23 is the same as the spiral direction of the thread of the male screw portion, and the lead is desirably set larger than the lead of the male screw portion. As a result, when the cooperating member (for example, a washer) rotates with the female screw body (for example, a piston) when the female screw body rotates in the loosening direction, the cooperating member is pressed against the female screw body by the difference in the lead, so that the first relative rotation prevention The mechanism A can be more firmly engaged to prevent loosening.

In the first to third embodiments, the outer seal fitting portion 210 formed on the peripheral surface of the piston member 100 is exemplified by the case where the piston ring 90 is brought into contact with the step portion 205 and positioned in the axial direction. However, the present invention is not limited to this. For example, as shown in FIG. 20, the inner peripheral surface of the piston ring 90 can be tapered

surfaces

90a, 90b to improve the sealing performance. In this case, the outer

seal fitting portions

210 and 56 are formed on the outer peripheral surface of the piston member 100 and / or the washer 50, and the tapered surfaces 203 facing the

tapers

90a and 90b of the piston ring 90 are formed on the respective peripheral surfaces. 55a may be formed. The tapered surface 203 has a large diameter on the seal portion 105a side and a small diameter on the end surface 101 side. That is, it inclines so that it may become a small diameter gradually toward the washer 50 side. The tapered surface 55a is inclined so as to gradually become smaller in diameter toward the piston member 100. By doing so, the clamping force between the piston member 100 and the washer 50 is used to closely contact the taper surfaces 90a and 90b of the piston ring 90 and the taper surfaces 203 and 55a of the piston member 100 and / or the washer 50 in the axial direction. Can be positioned.

Furthermore, in the modification shown in FIG. 8 of the first embodiment, the case where the inner seal member 82 is interposed between the tapered surface 11 of the shaft portion 12 of the linear motion rod 10 and the tapered surface 51 of the piston 50 is illustrated. However, the present invention is not limited to this. For example, as shown in FIG. 21, it is possible to install an inner seal member 82 on the main body portion 12 a of the linear motion rod 10 and make the outer periphery of the inner seal member 82 a tapered surface 11. The inner seal member 82 is positioned in the axial direction by contacting the stepped portion 21.

The insertion hole 50a of the linkage member 50 has a basic hole 50a2 and an annular inner seal accommodation hole 250 that continues from the middle of the insertion hole 50a to the end surface. The inner seal accommodation hole 250 has a tapered surface 51 at the inner periphery thereof, and the tapered surface 51 and the tapered surface 11 of the inner seal member 82 are brought into close contact with each other, thereby simultaneously positioning the linking member 50 in the axial direction. , Suppress oil leakage. At this time, if the fastening force of the piston member 100 is adjusted, the degree of close contact between the

tapered surfaces

11 and 51 can be changed as appropriate.

Further, in the first to third embodiments, the piston side taper surface is formed on the seat portion 102 of the piston member 100 and the self-excited centering with the washer 50 is exemplified. It is not limited to. For example, as in the modification of the third embodiment shown in FIG. 22A, in the insertion hole 100a in the piston member 10, the first insertion hole (inner seal housing hole) 100a1 having a large diameter and the second having a small diameter are used. The insertion hole (basic hole) 100a2 may be coaxial, and the inner seal member 82 may be accommodated in the first insertion hole (inner seal accommodation hole) 100a1. An annular tapered surface 82a is formed on the inner peripheral surface of the inner seal member 82, and the annular tapered surface 82a and the tapered surface 11 of the linear motion rod 10 are brought into contact with each other so that the piston member 100 and the linear motion are in direct motion. Direct centering between the rods 10 is also preferred.

Further, here, on the outer peripheral surface 105 of the piston member 10, an annular outer seal fitting portion 210 that continues from the middle to the end surface 101 is formed, and the piston ring 90 is inserted therein. A ring-shaped outer seal holding member 270 is fixed to the end surface 101 of the piston member 10 by a bolt 272 extending in the axial direction. By bringing the outer seal holding member 270 and the piston ring 90 into contact with each other, the piston ring 90 is prevented from dropping from the outer seal fitting portion 210.

Furthermore, in said 1st thru | or 3rd embodiment, the cooperation member (washer) 50 was comprised as a separate member from the linear motion rod 10, and illustrated the structure which prevents loosening of the piston member 100 using this cooperation member 50. However, the present invention is not limited to this. For example, as in a modification of the first embodiment shown in FIG. 22B, the linear motion rod 10 may be provided with a function equivalent to that of the cooperation member (washer) 50 in an integrated manner. That is, the linear motion rod 10 integrally has the extension portion 50X, and the first receiving portion 60 facing the seat portion 102 of the piston member 100 may be formed in the extension portion 50X. As a result, the first relative rotation prevention mechanism A is configured between the expansion portion 50 </ b> X of the linear motion rod 10 and the piston member 100. In the first relative rotation preventing mechanism A, when at least the piston member 100 tries to rotate in the loosening direction with respect to the linearly acting rod 10 to be screwed, the first receiving portion 60 and the seat portion 102 are engaged with each other. Prevent relative rotation.

At this time, a first insertion hole (inner seal accommodation hole) 100a1 having a large diameter and a second insertion hole (basic hole) 100a2 having a small diameter are formed in the insertion hole 100a of the piston member 100. The inner seal member 82 is accommodated in the first insertion hole (inner seal accommodating hole) 100a1, and the working fluid can be sealed by bringing the inner seal member 82 into contact with the end surface on the linear motion rod 10 side. .

In addition, in the said embodiment, although the case where the washer side contact part of a cooperation member (washer) becomes concave shape in the circumferential direction mainly is illustrated, you may be convex in the circumferential direction inner side.

23 (a) is a plan view of the seal structure 1 according to the fourth embodiment, and FIG. 23 (b) is a front view of the seal structure 1. FIG. FIG. 24 is a cross-sectional view taken along line AA in FIG. As shown in these drawings, the seal structure 1 seals the working fluid while fastening the piston member 100 to the linear motion rod 10 and fixing them to each other, and is formed in the linear motion rod 10 and the piston member 100. The first female screw portion 106a, the fixing female screw body 30, and the relative rotation preventing mechanism 40 are provided. The piston member 100 and the fixing male screw body 30 are “members to be inserted” into which the linear rod 10 is inserted, and the piston body 300 is constituted by these members.

As shown in FIG. 24, the linear motion rod 10 has a substantially rod-shaped (substantially cylindrical) main body portion 12a having a large diameter from the center toward the end portion, and a columnar positioning portion having a smaller diameter than the main body portion 12a. 12b and a cylindrical end portion 12c having a smaller diameter than the positioning portion 12b. Therefore, the first shaft side step portion 11a is formed at the boundary between the main body portion 12a and the positioning end portion 12b, and the second shaft side step portion 11b is formed at the boundary between the positioning end portion 12b and the end portion 12c. A male screw portion 13 in which a male screw spiral groove is formed is provided on the outer peripheral surface of the end portion 12c. In the present embodiment, the male screw portion 13 includes a first male screw spiral groove 14 that is a right screw, and a left screw. The two types of male screw spiral grooves 15 of the second male screw spiral groove 15 are overlapped on the same region.

FIG. 25 shows an enlarged view of the male thread portion 13 of the linear motion rod 10. The male screw portion 13 has a substantially crescent-shaped thread 13a continuous in a plane direction perpendicular to the axis (screw shaft) C, on one side (left side in the figure) and the other side (right side in the figure). By forming the screw thread 13a in this way, two types of spiral grooves, a spiral groove turning clockwise and a spiral groove turning counterclockwise, are formed between the screw threads 13a. I can do it.

In the present embodiment, by doing so, two types of male thread spiral grooves, the first male thread spiral groove 14 and the second male thread spiral groove 15, are formed in the male thread portion 13. Therefore, the male thread portion 13 can be screwed with any of the right and left thread female thread bodies. For the details of the male screw portion 13 in which two types of male screw spiral grooves are formed, refer to Japanese Patent No. 4666313 related to the inventor of the present application.

Returning to FIG. 24, the piston member 100 is a cylindrical member, and has an annular outer peripheral surface 105 facing the inner peripheral surface of the tube 4, a pair of end surfaces 101 facing in the axial direction, and coaxial with the outer peripheral surface. It has the insertion hole 100a formed in a shape. The outer peripheral surface 105 is close to the inner peripheral surface of the tube 4 and serves as a seal portion 105a that restricts the movement of the working fluid. At least one of the end surfaces 101 (here, both) serves as a pressure receiving surface 101a that receives the pressure of the working fluid. The linear motion rod 10 is inserted into the insertion hole 100a.

In detail, the insertion hole 100a has a first insertion hole (inner seal accommodation hole) 100a1 having a large diameter and a second insertion hole (basic hole) 100a2 having a small diameter coaxially. The first insertion hole 100a1 is located on the center side of the linear motion rod 10, and has a size slightly larger than the diameter of the main body portion 12a or the positioning portion 12b of the linear motion rod 10. The second insertion hole 100a2 is located on the shaft end side of the linear motion rod 10, and a first female thread portion 106a is formed on the inner peripheral surface. As a result, a hole-side stepped portion 100b is formed at the boundary between the first insertion hole 100a1 and the second insertion hole 100a2.

A cylindrical inner seal member 82 is disposed on the inner periphery of the first insertion hole (inner seal housing hole) 100a1 and on the outer periphery of the positioning portion 12b of the linear motion rod 10. The axial size of the inner seal member 82 is slightly longer than the axial dimension of the positioning portion 12 b of the linear motion rod 10. As a result, both ends of the inner seal member 82 are engaged with the hole side step portion 100b and the first shaft side step portion 11a. The outer diameter of the inner seal member 82 is substantially the same as the inner diameter of the first insertion hole 100a1.

As described above, when the end of the linear motion rod 10 is inserted into the first insertion hole 100a1 of the piston member 100, the outer peripheral surface of the inner seal member 82 comes into close contact with the inner peripheral surface of the first insertion hole 100a1 of the piston member 100. Furthermore, both end surfaces of the inner seal member 82 are in contact with the hole-side step portion 100b and the first shaft-side step portion 11a. That is, the linear motion rod 10 and the piston member 100 are positioned in the axial direction. The inner seal member 82 is set to be made of synthetic resin, but is not necessarily made of synthetic resin, and is not particularly limited as long as it can maintain hermeticity.

The outer peripheral surface 105 of the piston member 100 is formed with an annular outer seal fitting portion 210 that continues from the middle to the end surface 101 on the fixing female screw body 30 side. The outer seal fitting portion 210 forms a small diameter surface 201 that continues to the end face 101 on the fixing female screw body 30 side on the peripheral surface thereof, and the piston ring 90 is inserted into, contacted with and fitted into the outer ring fitting portion 210. The The small diameter surface 201 is smaller in diameter than the outer peripheral surface (seal portion 105a) of the piston member 100, and the piston ring 90 is positioned in the axial direction by the step 205 formed on the seal portion 105a and the small diameter surface 201. The axial dimension of the piston ring 90 is set to be slightly larger than the axial dimension of the small-diameter surface 201, and the piston ring 90 slightly protrudes from the piston member 100 to the fixing female screw body 30 side. The fixing female screw body 30 is set to have a diameter larger than that of the small-diameter surface 201. Therefore, when the fixing female screw body 30 and the piston member 100 are fastened, the end face of the fixing female screw body 30 comes into contact with the piston ring 90 and the piston ring 90 is fixed. That is, the piston ring 90 is sandwiched between the piston member 100 and the fixing female screw body 30. Accordingly, the fixing female screw body 30 is disposed in the vicinity of the end face of the piston member 100 and functions as an outer seal holding member that presses the piston ring 90 toward the outer seal fitting portion 210 side. Of course, the material of the piston ring 90 is not limited to synthetic resin, and is not particularly limited as long as it can maintain hermeticity.

The first female thread portion 106 a of the piston member 100 is screwed into the male thread portion 13 of the linear motion rod 10. Accordingly, the piston member 100 is fastened to the linear motion rod 10 by itself as an internal thread. Furthermore, a fixing female screw body 30 is screwed into the male screw portion 13 from the outside of the piston member 100. Therefore, the piston member 100 is fixed so as to be sandwiched between the inner seal member 82 and the fixing female screw body 30.

In the first female thread portion 106a of the piston member 100, a first female thread spiral groove that is a right-hand thread is formed. That is, the first female screw portion 106 a is screwed with the first male screw spiral groove 14 in the male screw portion 13 of the linear motion rod 10.

The external thread and the like of the fixing female screw body 30 are not particularly limited, but are substantially matched with the piston member 100 in the present embodiment. Accordingly, the outer peripheral surface 31 of the fixing female screw body 30 is a cylindrical surface. Further, the piston member 100 includes a screw hole 32 penetrating in the axial direction. A second female screw spiral groove that is a left-hand thread is formed in the second female screw portion 33 that is the inner peripheral surface of the screw hole 32. That is, the fixing female screw body 30 is screwed into the second male screw spiral groove 15 in the male screw portion 13 of the linear motion rod 10. The end surface 38 is provided with a relative rotation prevention mechanism 40 described later.

FIGS. 26A to 26D are views showing the relative screwing operation of the piston member 100 and the fixing female screw body 30 in a state where the relative rotation preventing mechanism is ignored. Since the piston member 100 and the fixing female threaded body 30 are in a reverse screw relationship with each other, as shown in FIGS. If they are (or both are fixed and the linear rod 10 is rotated), they will move in opposite directions along the axis C.

Specifically, as shown in FIG. 5A, the rotation direction of the piston member 100 and the fixing female screw body 30 with respect to the linear motion rod 10 is counterclockwise when viewed from the fixing female screw body 30 side (the upper side in the figure). In this case, the piston member 100 and the fixing female screw body 30 move in the direction of approaching each other along the direction of the axis C. However, when the piston member 100 and the fixing female screw body 30 are already in close contact with each other, the piston member 100 and the fixing female screw body 30 are naturally restricted from being simultaneously rotated.

Further, as shown in FIG. 5B, when the rotation direction of the piston member 100 and the fixing female screw body 30 is clockwise when viewed from the fixing female screw body 30 side (the upper side in the figure), the piston member 100 and the female screw body 30 for fixation move in the direction away from each other along the direction of the axis C. However, when the piston member 100 is already in contact with the inner seal member 82 (see FIG. 24), the piston member 100 cannot move any further, so the piston member 100 and the fixing female screw body 30 rotate simultaneously. Is naturally regulated.

Of course, as shown in FIG. 3C, when only the fixing female screw body 30 is rotated clockwise, the fixing female screw body 30 can be loosened. As a result, the piston ring 90 can be detached from the outer seal fitting portion 210. Further, as shown in FIG. 4D, when only the fixing female screw body 30 is rotated clockwise and at the same time the piston member 100 is rotated counterclockwise, both are loosened simultaneously.

As can be understood from the above screwing operation, when the piston member 100 and the fixing female screw body 30 are sufficiently fastened to the linear motion rod 10, the piston member 100 and the fixing female screw body 30 rotate in the same direction. Is structurally impossible (see FIGS. 26A and 26B). In other words, the linear motion rod 10 cannot be rotated relative to the piston member 100 and the fixing female screw body 30. On the other hand, it can be understood that the fastening state is loosened when only the fixing female screw body 30 rotates or when the piston member 100 and the fixing female screw body 30 are rotated in opposite directions. That is, in this fastening structure, if the “relative rotation after fastening” of the piston member 100 and the fixing female screw body 30 is restricted, the piston member 100 and the fixing female screw body 30 can be maintained in a state in which they are not structurally detached. As a result, the piston ring 90 does not come off permanently.

Based on the above considerations, the relative rotation prevention structure 40 employed in the present embodiment will be described.

Referring back to FIG. 24, the relative rotation preventing mechanism 40 includes a first engagement hole 191 that is a female screw hole formed in the piston member 100, a second engagement hole 181 that is formed in the female screw body 30 for fixation, The external male screw body 110 and the annular washer 150 are provided. The second engagement hole 181 is an insertion hole, and the first engagement hole 191 formed in the piston member 100 is a non-insertion hole. An engaging female thread portion is formed on the inner peripheral surface of the first engaging hole 191. The engaging male screw body 110 is screwed into the first engaging hole 191 through the second engaging hole 181. As a result, the engaging male screw body 110 is consistently inserted into the first engaging hole 191 and the second engaging hole 181, and the relative rotation of the piston member 100 and the fixing female screw body 30 is restricted. The female screw hole may be formed not on the first engagement hole 191 side but on the second engagement hole 181 side.

As shown in FIG. 27, the engaging male screw body 110 is a so-called bolt, and has a head portion 120 and a shaft portion 130. A screw body side seat portion 122 is formed in a portion corresponding to a lower portion or a root of the head portion 120. The shaft portion 130 is formed with a cylindrical portion 130a and a screw portion 130b. Of course, the cylindrical portion 130a is not essential.

A first receiving portion 160 is formed on one side of the washer 150 (the upper surface side in FIG. 27). This 1st receiving part 160 has opposed the screw body side seat part 122, and the 1st engagement mechanism A is comprised among both. In the first engagement mechanism A, when at least the screw body side seat portion 122 tries to rotate in the direction of loosening the engaged male screw body 110, the first receiving portion 160 and the screw body side seat portion 122 engage with each other. Thus, relative rotation between the first receiving portion 160 and the screw body side seat portion 122 with respect to the rotation direction is prevented.

A second receiving portion 170 is formed on the other side of the washer 150 (the lower surface side in FIG. 27). The second receiving portion 170 faces the fixing female screw body 30.

A member side seat portion 182 that faces the second receiving portion 170 of the washer 150 is formed on the fixing female screw body 30. A second engagement mechanism B is configured between the member side seat portion 182 of the fixing female screw body 30 and the second receiving portion 170 of the washer 150. In this second engagement mechanism B, when at least the washer 150 tries to rotate in the loosening direction together with the engaging male screw body 110, the second receiving portion 170 and the member side seat portion 182 engage with each other, and the rotation direction Relative rotation between the second receiving portion 170 and the member side seat portion 182 is prevented.

When the engagement male screw body 110 tries to rotate in the loosening direction by the action of the first engagement mechanism A and the second engagement mechanism B, the engagement male screw body 110 and the fixing female screw body 30 are interposed by the washer 150. Relative rotation is restricted. As a result, the engaging male screw body 110 is prevented from loosening.

As shown in FIG. 28, as the first engagement mechanism A, the screw body side unevenness 124 is formed on the screw body side seat portion 122 of the male screw body 110 for engagement. The screw body side unevenness 124 has a saw blade shape that is continuously provided in the circumferential direction. The direction in which each of the threaded body side irregularities 124 extends, that is, the direction in which the ridge line extends, is the radial direction of the engaging male threaded body 110. As a result, the screw body side unevenness 124 extends radially from the axis.

Furthermore, the threaded body side seat portion 122 is formed with a threaded body side tapered surface 126 inclined in the radial direction. Since the screw body side tapered surface 126 is inclined so that the center side approaches the screw tip, as a result, a convex conical shape is formed on the screw tip side. More preferably, the aforementioned threaded body side unevenness 124 is formed on the threaded body side tapered surface 126.

As shown in FIG. 29, as the first engagement mechanism A, the first receiving portion 160 of the washer 150 is formed with a first receiving portion-side unevenness 164 that engages with the screw body-side unevenness 124. The 1st receiving part side unevenness | corrugation 164 becomes the saw blade shape provided in multiple numbers by the circumferential direction. The direction in which each of the first receiving part side irregularities 164 extends, that is, the direction in which the ridge line extends, is along the radial direction of the engaging male screw body 110. As a result, the first receiving portion side unevenness 164 extends radially from the center of the through hole 152 of the washer 150.

Further preferably, the first receiving portion 160 is formed with a washer-side tapered surface 166 inclined in the radial direction. The washer-side tapered surface 166 has a mortar shape that is inclined so that the center side approaches the screw tip, and as a result, has a concave conical shape on the screw tip side. On the washer side tapered surface 166, the first receiving portion side unevenness 164 described above is formed.

As a result, when the engaging male screw body 110 is tightened, in the first engagement mechanism A, the screw body side tapered surface 126 of the screw body side seat portion 122 enters the recess of the washer side tapered surface 166 of the washer 150, and the screw body side The unevenness 124 and the first receiving portion side unevenness 164 are engaged. As shown in FIG. 30 (A), when the engaging male screw body 110 tries to rotate in the fastening direction Y, the

inclined surfaces

124Y and 164Y come into contact with each other, and the distance between the two is determined in the axial direction. Allow relative sliding while releasing. On the other hand, when the engaging male screw body 110 attempts to rotate in the loosening direction X, the mutually perpendicular surfaces (surfaces with a strong inclination) 124X and 164X come into contact with each other to prevent relative movement between the two. In particular, the first engagement mechanism A engages the screw body side unevenness 124 and the first receiving portion side unevenness 164 as the distance between the screw body side seat portion 122 and the first receiving portion 160 decreases by tightening the engaging male screw body 110. And the engagement strength on the loosening direction X side is increased. Here, the inclination angle of the screw body side taper surface 126 and the inclination angle of the washer side taper surface 166 are made different from each other. In particular, the inclination angle from the axis of the washer side taper surface 166 is set to the axis of the screw body side taper surface 126. By setting it to be narrower than the inclination angle from, it is possible to tighten without rattling regardless of the pitch of the sawtooth formed on each tapered surface.

29, the distance from the screw shaft center of the outer wall 172 of the second receiving portion 170 of the washer 150 varies along the circumferential direction. Specifically, the outer wall 172 has a circular shape that is eccentric with respect to the axial center of the screw (the center of the insertion hole 152).

On the other hand, the member side seat portion 182 of the fixing female screw body 30 includes a fitting portion 184 for accommodating the second receiving portion 170 of the washer 150, and the inner wall of the fitting portion 184 is also made of a screw. It has a circular shape that is eccentric with respect to the shaft center. The amount of eccentricity is the same in the second receiving portion 170 and the fitting portion 184, and the diameter difference (margin gap) between the second receiving portion 170 and the fitting portion 184 is set smaller than the amount of eccentricity.

Therefore, as shown in FIG. 27, when the second receiving portion 170 of the washer 150 is accommodated in the fitting portion 184 of the fixing female screw body 30, both are fitted together, and the screw shafts are aligned. As it is, relative rotation in the circumferential direction of both is restricted. That is, the second receiving part 170 and the fitting part 184 act as the second engagement mechanism B.

As a result, according to the relative rotation preventing mechanism 40, the first engagement mechanism A is configured between the screw body side seat portion 122 and the first receiving portion 160 by interposing the washer 150. When the second engaging mechanism B is configured between the second receiving portion 170 and the engaging male screw body 110 is about to be loosened, the restricting action of both the first engaging mechanism A and the second engaging mechanism B is performed. The engaging male screw body 110 is engaged with the fixing female screw body 30 in the circumferential direction, and is prevented from rotating backward, that is, loosening. Therefore, even if vibration etc. arise, the fastening state which does not loosen at all can be obtained. As a result, the engaging male screw body 110 can reliably restrict the relative rotation of the piston member 100 and the fixing female screw body 30.

Furthermore, here, as the first engagement mechanism A, the screw body side unevenness 124 and the first receiving portion side unevenness 164 have a saw blade shape that is continuous in the circumferential direction, and acts as a so-called ratchet mechanism or one-way clutch mechanism. . As a result, during the fastening operation, the screw body side unevenness 124 and the first receiving portion side unevenness 164 are allowed to move relative to each other to realize a smooth relative rotation, while during the loosening operation, the screw body side unevenness 124 and the first receiving portion. The relative movement of the side irregularities 164 is completely restricted. As a result, workability at the time of fastening and subsequent locking can be rationally achieved.

Further, as the first engagement mechanism A, the threaded body side seat part 122 and the first receiving part 160 are formed with the threaded body side tapered surface 126 and the washer side tapered surface 166, so that the contact area between them can be increased. I can do it. Further, the fastening force in the axial direction of the engaging male screw body 110 also acts in the radial direction by the tapered surface. By pressing the taper surfaces of each other in the radial direction, centering can be carried out by self-excitation. As a result, the concentricity between the engaging male screw body 110 and the washer 150 is increased, and the engagement accuracy of the screw body side unevenness 124 and the first receiving portion side unevenness 164 can be increased. It is also preferable to slightly increase the inclination of the convex thread body side tapered surface 126 and to slightly decrease the inclination angle of the concave washer side tapered surface 166 to provide a small difference in angle. If it does in this way, a mutual taper surface can be made to contact | abut little by little toward the radial direction outer side from the center with the increase in clamping pressure.

In the second engagement mechanism B, the outer wall of the second receiving portion 170 of the washer 150 and the inner wall of the fitting portion 184 of the fixing female screw body 30 are prevented from being concentric with respect to the axis of the screw. is doing. In other words, the distance from the axial center of the screw of the inner wall of the fitting part 184 and the outer wall of the second receiving part 170 changes along the circumferential direction. With this shape, when the inner wall of the fitting portion 184 and the second receiving portion 170 are fitted together, relative rotation in the circumferential direction is restricted while keeping the axial centers thereof aligned. In particular, here, since it has an eccentric circular shape, it is possible to prevent relative rotation between the two while making the shape processing of the washer 150 and the fixing female screw body 130 extremely simple.

In addition, although the case where the screw body side unevenness | corrugation 124 and the 1st receiving part side unevenness | corrugation 164 were saw-tooth shape was illustrated as the 1st engagement mechanism A here, this invention is not limited to this. For example, as shown in FIG. 30B, the unevenness of each other can be a mountain shape (both are inclined surfaces). Thus, when the engaging male screw body 110 rotates in the loosening direction X, the

inclined surfaces

124X and 164X tend to move relative to each other. The side irregularities 164 are about to leave. If this moving distance (the angle α to leave) is set to be larger than the lead angle of the engaging male screw body 110, the screw body side unevenness 124 and the first receiving portion side unevenness 164 are further increased even if the engaging male screw body 110 tries to loosen. Will not be able to relax. In FIG. 30B, the unevenness of the isosceles triangle is illustrated as an example. However, as shown in FIG. It is also preferable to make the inclination angles of the

inclined surfaces

124X and 164X in contact with each other gentle. In this way, the circumferential distance P between the

inclined surfaces

124Y and 164Y that must be overcome during the fastening rotation can be shortened, so that looseness (gap) after fastening can be reduced.

Further, as an application of FIGS. 30A to 30C, as shown in FIG. 30D, corrugated irregularities with curved ridges and valleys are also preferable. Smooth operability can be obtained during fastening. Furthermore, although the unevenness | corrugation extended in a radial direction was illustrated here, as shown to FIG. 31 (A), it is also preferable to form a spiral-shaped groove | channel or a peak (unevenness | corrugation). In addition, as shown in FIG. 31B, even a linearly extending groove or mountain (unevenness) can be inclined so that the circumferential phase changes with respect to the radial direction of the screw. In addition, as shown in FIG. 31C, it is also preferable to adopt a so-called embossed shape in which a plurality of fine irregularities are formed both in the circumferential direction and the radial direction (planar shape) of the screw.

Further, unlike the relative rotation prevention mechanism 40, the uneven shapes of the screw body side unevenness 124 and the first receiving portion side unevenness 164 are not necessarily matched (similar). For example, different shapes from the various shapes in FIGS. 30 and 31 can be selected and combined with each other.

As an application of the relative rotation prevention mechanism 40, as shown in FIG. 32A, the outer wall of the second receiving portion 170 of the washer 150 and the inner wall of the fitting portion 184 of the member side pedestal portion 182 are the axial center of the screw. On the other hand, a concentric partial arc shape S can be used, and the rest can be cut into a straight line like the chord G. That is, also in this case, the distance from the axial center of the screw of the inner wall of the fitting portion 184 and the outer wall of the second receiving portion 170 varies along the circumferential direction. Therefore, the inner wall of the fitting portion 184 and the second receiving portion 170 are engaged by the shape of the string G, and relative rotation in the circumferential direction is restricted.

As shown in FIG. 32B, the outer wall of the second receiving portion 170 of the washer 150 has a partial arc shape S concentric with the axial center of the screw, and a protrusion T extending in the radial direction is formed in the remaining portion. I can do it. At this time, a recess K recessed in the radial direction is formed on the inner wall of the fitting portion 184. By the engagement of the protrusion T and the recess K, the inner wall of the fitting portion 184 and the second receiving portion 170 are engaged, and the relative rotation in the circumferential direction is restricted. At this time, it is preferable that the recess K formed in the fitting portion 184 has a small perfect circular shape (partial arc). This is because, when the fitting portion 184 is cut, the depression K can be formed by only one processing with the rotary blade. Although not particularly illustrated, a recess (notch) may be formed on the second receiving portion 170 side of the washer 150, and a protrusion protruding radially inward may be formed on the fitting portion 184 side.

According to the seal structure 1 of the fourth embodiment, both the inner seal member 82 and the piston ring (outer seal member) 90 can be inserted from the end faces of the fixing female screw body 30 and the piston member 100. The inner seal member 82 can be held by the fixing female screw body 30 and the linear rod 10, and the piston ring 90 can be held by the fixing female screw body 30 and the piston member 100. As a result, the assembly work becomes extremely easy.

Furthermore, according to this seal structure 1, since the piston member 100 itself has the first female screw portion 106a and is screwed with the first male screw spiral groove 14 of the linear motion rod 10, the force received from the outside is The piston member 100 itself can transmit to the linear motion rod 10. The minimum diameter (valley diameter) of the first male screw spiral groove 14 is increased as compared with a conventional structure in which a piston member slidable in the axial direction is fixed to the linear motion rod 10 so as to be sandwiched between female screw bodies. Thus, the durability of the linear motion rod 10 can be increased.

The male screw portion 13 of the linear rod 10 has a first male screw spiral groove 14 and a second male screw spiral groove 15, and a piston member is formed by a fixing female screw body 30 screwed into the second male screw spiral groove 15. Since the rotation in the loosening direction of 100 is restricted, the piston member 100 does not loosen even if repeated external force or vibration acts on the piston member 100. As a result, the inner seal member 82 and the piston ring (outer seal member) 90 are not detached. In addition, unlike conventional loosening prevention, it does not rely on the frictional force between the flank surface of the male thread body and the flank surface of the female thread body. Since the structural interference is prevented from loosening due to the operation interference, it is not necessary to retighten the fixing female screw body 30 more than necessary, and the fatigue of the linear motion rod 10 can be reduced simultaneously with facilitating the fastening operation. Further, deterioration of the inner seal member 82 and the piston ring (outer seal member) 90 held by the fastening force of the fixing female screw body 30 is also reduced.

Similarly, as long as the relative rotation prevention mechanism 40 does not come off or breakage occurs, even if the piston member 100 is plastically deformed or worn, a situation in which the piston member 100 falls off the linear motion rod 10 is not possible. It will be surely prevented and safety can be improved.

The first male screw spiral groove 14 to which the piston member 100 is screwed and the second male screw spiral groove 15 to which the fixing female screw body 30 are screwed have a common minimum diameter (valley diameter). When the fixing member 100 and the fixing female screw body 30 are brought into close contact with each other, the external force acting on the piston member 100 is dispersed by the piston member 100 and the fixing female screw member 30 to the first male screw spiral groove 14 and the second male screw spiral groove 15. Can communicate. This also increases the durability of the linear motion rod 10.

Further, in the present embodiment, the relative rotation preventing mechanism 40 completely prevents the relative rotation of the piston member 100 and the fixing female screw body 30. Therefore, only the fixing female screw body 30 rotates, and the linear motion rod 10 alone. To prevent it from coming off. In particular, in the relative rotation prevention mechanism 40, the engagement male screw body 110 itself that engages with the piston member 100 and the fixing female screw body 30 is also prevented from rotating in the loosening direction. There is no end. As a result, even if vibration or the like occurs, the function of the relative rotation prevention mechanism 40 is maintained, so that it is possible to prevent the piston member 100 from dropping from the linear motion rod 10.

Further, when it is necessary to remove the piston member 100 during maintenance of the inner seal member 82 and the piston ring (outer seal member) 90, the first engagement mechanism A between the washer 150 and the engagement male screw body 110, Alternatively, the engagement of any of the second engagement mechanisms B between the washer 150 and the fixing female screw body 30 is broken, the engaging male screw body 110 is removed, and then the fixing female screw body 30 is removed and then fixed. The female screw body 30 is loosened. In this way, by limiting the destruction target at the time of maintenance to the washer 150 and the engaging male screw body 110, the piston member 100, the linear motion rod 10, and the fixing female screw body 30 can be reused. That is, according to the present embodiment, the piston member 100, the fixing female screw body 30, and the linear motion rod 10 can be easily and easily maintained while completely preventing displacement and dropping of the piston member 100 after assembly from the linear motion rod 10. It becomes possible to carry out at low cost. When the material of the washer 150 or the engaging male screw body 110 is selected to be softer than the material of the piston member 100 or the fixing female screw body 30, the washer 150 can be removed when the engaging male screw body 110 is forcibly removed. Alternatively, the engaging male screw body 110 can be preferentially broken.

Next, with reference to FIG. 33, a seal structure according to a fifth embodiment of the present invention will be described. In addition, since it is the same as that of 4th embodiment except a relative rotation prevention mechanism, it demonstrates limiting to a relative rotation prevention mechanism here. In this relative rotation prevention mechanism, the engaging male screw body 110 is the same as that in the fourth embodiment, but the structures of the washer 150 and the fixing female screw body 130 are partially different. A description of the combined male screw body 110 is omitted.

As shown in FIG. 34 (A), the washer 150 is thinner than the fourth embodiment, and also protrudes in the screw tip direction on the second receiving portion 170 side facing the fixing female screw body 30. A second washer-side tapered surface 176 is formed.

As in the fourth embodiment, the outer wall 172 of the second receiving portion 170 of the washer 150 and the inner wall of the fitting portion 184 have an eccentric circular shape. Rotation is regulated.

33, a member-side tapered surface 186 that is concave on the screw tip side is formed on the bottom surface of the fitting portion 184 of the female screw body 130 for fixation. As a result, the fastening force of the male screw body 110 is received via the washer 150 by contacting the second washer-side tapered surface 176 of the washer 150.

Furthermore, a pulling space 188 is formed in a part of the inner wall of the fitting portion 184. The pulling space 188 is secured by expanding the inner wall of the fitting portion 184 radially outward and increasing the depth of the recess. The pulling space 188 forms a gap in a part of the outer wall of the second receiving part 170 of the washer 150.

When the fixing female screw body 30 is fixed using the engaging male screw body 110 and the washer 150, the first engaging mechanism A serves as the screw body side unevenness 124 of the engaging male screw body 110 and the first receiving portion side on the washer 150 side. Concavities and convexities 164 engage. Further, as the second engagement mechanism B, the outer wall of the second receiving portion 170 of the washer 150 and the inner wall of the fitting portion 184 are fitted to each other, whereby circumferential rotation is restricted. As a result, the reverse rotation of the engaging male screw body 110 is prevented, i.e., does not loosen.

FIG. 34B illustrates an operation for forcibly loosening the engaging male screw body 110 during maintenance of the inner seal member 82 and the piston ring (outer seal member) 90, and the like. For example, by inserting the tip of the minus driver D into the pulling space 188, the tip is inserted into the back side of the washer 150. In this state, the second receiving part 170 of the washer 150 can be deformed upward by lifting the tip of the minus driver D. As a result, the second engagement mechanism B by the second receiving portion 170 and the fitting portion 184 is released. If the engaging male screw body 110 is rotated in the loosening direction in this state, the washer 150 can also be rotated together, so that the engaging male screw body 110 can be loosened.

In the fifth embodiment, the case where the pulling space 188 is formed in the fitting portion 184 of the fixing female screw body 30 is exemplified, but the present invention is not limited to this. For example, as shown in FIG. 35A, by forming an inclined surface 177A on the outer wall of the washer 150, the tip of the minus driver D can be inserted into the back side of the washer 150 (the fixing female screw body 30 side). To. Further, as shown in FIG. 35B, an insertion recess 177B is formed on the periphery of the washer 150 so as to be away from the fixing female screw body 30. The tip of the minus driver D can be inserted into the back side of the washer 50 through the insertion recess 177B. In addition, a crescent-shaped gap is created by utilizing the difference in diameter between the outer diameter of the washer 150 and the inner diameter of the fitting portion 184, and this crescent-shaped gap (not shown) is used to It is also preferable that the tip can be inserted into the back side of the washer 150. Of course, such a gap is not limited to a crescent shape.

Next, with reference to FIG. 36, a seal structure according to a sixth embodiment of the present invention will be described. In addition, since it is the same as that of 4th embodiment except a relative rotation prevention mechanism, it demonstrates limiting to a relative rotation prevention mechanism here. As shown in FIG. 36 (B), the threaded body side seat portion 122 of the engaging male threaded body 110 has a planar shape, and a saw blade shaped threaded body side unevenness 124 is formed there. Further, a constriction 132 for holding the washer 150 is formed at the root of the shaft portion 130 of the engaging male screw body 110.

36 (A), the first receiving portion 160 of the washer 150 has a planar shape, and a saw blade-shaped first receiving portion side unevenness 164 is formed there. The insertion hole 152 of the washer 150 is formed with an engaging protrusion 152A that protrudes toward the inner peripheral side, and engages with the constriction 132 of the engaging male screw body 110. As a result, it is possible to integrate (couple) the engaging male screw body 110 and the washer 150 in advance.

Furthermore, a washer side step 174 extending in the axial direction of the screw is formed in the second receiving portion 170 of the washer 150. Here, the washer side stepped portion 174 is constituted by a claw bent toward the fixing female screw body 30 side.

On the other hand, the fixing female screw body 30 has a flat surface portion 31a as the member side step portion 182A of the member side seat portion 182. The flat portion 31 a is formed by cutting out a part of the cylindrical outer peripheral surface 31. The member-side step 182A is a step that falls to the screw tip side. The distances from the screw shaft centers of the washer side step 174 and the member side step 182A coincide with each other. Therefore, as shown in FIG. 36 (C), when the male thread body 110 for engagement is tightened, the washer side step 174 and the member side step 182A are engaged, and the washer 150 and the fixing female thread body 30 are relatively rotated. Is prevented.

In the sixth embodiment, the case where the two are integrated in advance by the constriction 132 of the engaging male screw body 110 and the engaging protrusion 152A of the washer 150 is illustrated, but the method is not limited to this. For example, it is possible to integrate the engaging male screw body 110 and the washer 150 by a magnetic force by giving magnetism to at least one of them. In addition, the engaging male screw body 110 and the washer 150 can be integrated in advance by an adhesive, (spot) welding, or press-fitting (frictional force). Further, it is possible to integrate the engaging male screw body 110 and the washer 150 using an auxiliary tool such as an O-ring.

In the sixth embodiment, the flat portion 31a formed on the outer peripheral surface 31 of the fixing female screw body 30 is engaged with the washer 150 so as to prevent relative rotation therebetween. However, the present invention is limited to this. Not. For example, as in the application example shown in FIG. 37A, a shaft engaging portion 175 can be formed on the washer 150, and the shaft engaging portion 175 can be engaged with the male screw portion 13 of the linear rod 10. The shaft engaging portion 175 has a ring shape surrounding the male screw portion 13, and the washer 150 and the male screw portion 13 are engaged by inserting the male screw portion 13 into the shaft engaging portion 175. As a result, relative rotation of the washer 150 and the fixing female screw body 30 is prevented. The shape of the shaft engaging portion 175 is not limited to the ring shape, but engages with the male screw portion 13 such as a partial arc shape shown in FIG. 37B or a V shape sandwiching the male screw portion 13. Any possible shape can be selected. Further, as shown in FIG. 37 (C), two or more bolt insertion holes are provided for one washer 150, and rotation around the other bolt axis is prevented by two or more engaging male screw bodies 110. It is also possible to configure.

Furthermore, in the sixth embodiment, the case where the washer side stepped portion 174 is formed on the outer periphery of the washer 150 is exemplified, but the present invention is not limited to this. For example, as shown in FIG. 37D, a washer side step (projection) 174 can be formed inside the outer edge of the washer 150. A member-side step (dent) 182 </ b> A that accommodates the washer-side step 174 is formed in the fitting portion 184 of the female screw body 30 for fixing. As a result, the washer side step (projection) 174 and the member side step (depression) 182A are engaged to prevent relative rotation.

Next, with reference to FIG. 38, a seal structure according to the seventh embodiment of the present invention will be described. In addition, since it is the same as that of 4th embodiment except a relative rotation prevention mechanism, it demonstrates limiting to a relative rotation prevention mechanism here. As shown in FIG. 38A, the outer shape of the washer 150 is a circular shape that is eccentric with respect to the axial center of the screw. The washer 150 is a so-called disc spring, and elastically deforms in the axial direction when receiving a fastening force from the engaging male screw body 110.

38 (B), the washer 150 is accommodated in an eccentric circular fitting portion 184 formed in the fixing female screw body 30. As shown in FIG. The threaded body side seat portion 122 of the engaging male threaded body 110 has a threaded body side unevenness 124 formed on the center side, and engages with the first receiving portion side unevenness 164 of the washer 150. Further, on the outer side of the screw body side unevenness 124 in the screw body side seat portion 122, a pressing surface 123 that directly contacts the fixing female screw body 30 is formed.

Furthermore, the gap L between the bottom surface of the fitting portion 184 and the threaded body side unevenness 124 of the engaging male threaded body 110 is set slightly smaller than the axial dimension of the washer 150. As a result, when the engaging male screw body 110 is tightened, the washer 150 is elastically deformed by being sandwiched between the bottom surface of the fitting portion 184 and the screw body side unevenness 124. However, the amount of elastic deformation is sufficient to prevent relative rotation between the screw body side unevenness 124 and the first receiving portion side unevenness 164. This is because the fastening force of the engaging male screw body 110 is directly transmitted to the fixing female screw body 130 via the pressing surface 123. According to the present embodiment, the strength and rigidity of the washer 150 itself can be lowered, so that the manufacturing cost can be reduced.

Further, in the fourth to seventh embodiments, the case where the head 120 of the engaging male screw body 110 protrudes from the fixing female screw body 30 is illustrated, but the depth of the fitting portion 184 of the fixing female screw body 30 is increased. Then, even the head 120 can be accommodated in the fitting portion 184.

In the fourth to seventh embodiments, the washer 150 is exemplified only when the outer shape of the washer 150 is a circle or a partial arc, but other shapes can be employed. For example, the outer shape of the washer 150 may be oval, oval, polygonal or the like. In other words, in order to prevent relative rotation by fitting with the fitting portion, it is sufficient if the outer shape of the washer 150 is “non-perfect circle (not a concentric perfect circle)” with respect to the shaft center. In the seventh embodiment, the case where the washer 150 is elastically deformed as a disc spring is illustrated. However, the washer 150 can be elastically deformed like a spring washer. Furthermore, it is also preferable that a washer is formed of a composite material in which a metal and an elastically deformable material (for example, rubber) are integrated so as to be elastically deformable.

Further, in the fourth to seventh embodiments, the washer 150 is installed on the fixing female screw body 30, and the first receiving portion side unevenness 164 is formed on the washer 150 b so as to be engaged with the screw body side unevenness 124 of the engaging male screw body 110. Although the structure to combine is illustrated, this invention is not limited to this. For example, as shown in FIG. 39, it is possible to directly form the first receiving portion side unevenness 164 on the plane of the fixing female screw body 30 and omit the washer 150. If the material strength of the fixing male screw body 30 is made stronger than that of the engaging male screw body 110, the first receiving portion of the fixing female screw body 30 even if the engaging male screw body 110 is forcibly loosened during maintenance or the like. The side irregularities 164 need not be damaged.

Next, the seal structure according to the eighth embodiment of the present invention will be described with reference to FIG. In addition, since it is the same as that of 4th embodiment except a relative rotation prevention mechanism, it demonstrates limiting to a relative rotation prevention mechanism here.

As shown in FIG. 40A, the relative rotation preventing mechanism 40 includes a first engagement hole 191 that is a female screw hole formed in the piston member 100 and a second engagement hole that is formed in the female screw body 30 for fixation. 181, an engagement pin 111 as an engagement member, a spring 113 as an urging means, and a male screw body 115 for release. The second engagement hole 181 is an insertion hole, and includes a large diameter hole 181A formed on the piston member 100 side and a small diameter hole 181B formed on the shaft end side and smaller than the large diameter hole 181A. A release female screw portion 181C for screwing with the release male screw body 115 is formed on the inner peripheral surface of the small diameter hole 181B.

The first engagement hole 191 formed in the piston member 100 is a non-insertion hole and is set to have the same diameter as the large diameter hole 181A and longer than the large diameter hole 181A. The engagement pin 111 is a rod member having a diameter substantially coincident with the inner diameters of the first engagement hole 191 and the large diameter hole 181A, and is longer than the large diameter hole 181A and shorter than the first engagement hole 191. The spring 113 is housed on the back side (bottom side) of the first engagement hole 191 and biases the engagement pin 111 housed in the first engagement hole 191 toward the fixing female screw body 30 side. .

Therefore, when the axial centers of the first engagement hole 191 and the large diameter hole 181A do not coincide with each other, the engagement pin 111 is completely accommodated in the first engagement hole 191 against the force of the spring 113. Is done. On the other hand, when the axial centers of the first engagement hole 191 and the large diameter hole 181A coincide, a part of the engagement pin 111 enters the large diameter hole 181A and stops by the urging force of the spring 113. As a result, the engaging pin 111 is inserted into the first engaging hole 191 and the second engaging hole 181 (large diameter hole 181A) at the same time, and the relative rotation of the piston member 100 and the fixing female screw body 30 is restricted. The

When releasing the restriction by the engaging pin 111 during maintenance or the like, the release male screw body 115 is inserted into the small diameter hole 181B and screwed with the release female screw portion 181C. Since the length of the shaft portion of the male screw body for release 115 is substantially the same as the axial length of the female screw body for fixing 30, as shown in FIG. The combination pin 111 can be pushed into the first engagement hole 191 side, and the restriction of relative rotation by the engagement pin 111 can be released. Accordingly, if the release male screw body 115 is screwed into the small diameter hole 181B, the fixing female screw body 30 can be easily loosened.

In the fourth to eighth embodiments, the structure in which the piston member 100 is disposed on the center side of the linear motion rod 10 and the fixing female screw body 30 is disposed on the end portion side of the linear motion rod 10 is illustrated. Is not limited to this. For example, as shown in FIG. 41, the piston member 100 may be disposed on the end portion side of the linear motion rod 10, and the fixing female screw body 30 may be disposed on the central side of the linear motion rod 10. In this case, a first insertion hole (inner seal accommodation hole) 35a1 having a large diameter and a second insertion hole (basic hole) 35a2 having a small diameter are coaxially provided inside the fixing female screw body 30. A second female thread portion 33 is formed on the inner peripheral surface of the insertion hole 35a2. As a result, the step of the boundary between the first insertion hole 35a1 and the second insertion hole 35a2 is brought into contact with the end surface of the inner seal member 82, so that the working fluid seal and the fixing male screw body 30 can be positioned in the axial direction. It becomes. The relative rotation preventing unit 40 may be inserted by inserting the engaging male screw body 110 from the fixing female screw body 30 side toward the piston member 100, but on the contrary, from the piston member 100 to the fixing member. The structure may be such that the engaging male screw body 110 is inserted toward the female screw body 30.

Furthermore, in the fourth to eighth embodiments, the case where the first male screw spiral groove 14 and the second male screw spiral groove 15 are formed so as to overlap the entire axial direction of the male screw portion 13 of the linear motion rod 10 is illustrated. However, the present invention is not limited to this. As shown in FIG. 42, for example, when the piston member 100 is disposed on the center side of the linear motion rod 10 and the fixing female screw body 30 is disposed on the end side, the first male screw spiral groove 14 to be screwed with the piston member 100 is a male screw. The second male screw spiral groove 15 to be screwed with the fixing female screw body 30 is an area where the fixing female screw body 30 is screwed, starting from the shaft end of the male screw portion 13, which is necessary throughout the axial direction of the portion 13. It suffices if it is formed up to the vicinity. That is, the male screw portion 13 of the present invention includes a case where the first male screw spiral groove 14 and the second male screw spiral groove 15 are formed so as to overlap each other in a limited region.

Further, in the fourth to eighth embodiments, the case where the lead directions of the first male screw spiral groove 14 and the second male screw spiral groove 15 are different (a right screw and a left screw are used) is illustrated. It is not limited. For example, as shown in an enlarged view in FIG. 43, the first male screw spiral groove 14 and the second male screw spiral groove 15 may have the same screw direction (lead direction) and different leads (lead angles). Good. In this case, as shown in the figure, by forming a further spiral groove on the spiral thread 13a formed by the first male screw spiral groove 14, the first male screw spiral having a lead L1 (lead angle θ1). The second male screw spiral groove 15 having the groove 14 and the lead L2 (lead angle θ2) can be formed with the screw directions aligned.

Furthermore, the male thread portion 13 of the linear motion rod 10 may not be formed by overlapping the first male thread spiral groove 14 and the second male thread spiral groove 15. For example, like the male screw portion 13 shown in FIG. 44, the first male screw spiral groove 14 has a large diameter, and the second male screw spiral groove 15 has a small diameter. It is also possible to arrange the second male screw spiral groove 15 so as not to overlap the end side. In this case, when the piston member 10 is screwed into the first male screw spiral groove 14, the second male screw spiral groove 15 is prevented from interfering in the diameter direction, and the fixing female screw body 30 is screwed into the second male screw spiral groove 15. In doing so, the first male screw spiral groove 14 may be prevented from interfering in the axial direction.

Next, with reference to FIG. 45, a seal structure according to the ninth embodiment of the present invention will be described. Since the relative rotation prevention mechanism is the same as that of the fourth embodiment, the description of the relative rotation prevention mechanism is omitted here, and only the parts different from the fourth embodiment will be described.

In the present embodiment, the inner seal member 82 formed of a chemical material such as a thermoplastic resin or a thermosetting resin with respect to the first shaft side step portion 11a of the linear motion rod 10 is connected to the metal expansion ring 11. The inner seal member 82 itself also serves as a stopper for positioning the piston member 100 in the axial direction. The inner seal member 82 may be directly engaged with the first shaft side step portion 11a, but in this case, the step of the first shaft side step portion 11a needs to be increased. Therefore, as in the present embodiment, the step of the first shaft side step portion 11a formed directly on the linear motion rod 10 is kept small, and the metal expansion ring 11 is engaged therewith, thereby substantially Increase the step.

On the other hand, the first insertion hole 100a1 of the piston member 100 serves as an inner seal accommodation hole 250 for accommodating the inner seal member 82. The inner seal member 82 is formed with a tapered surface 82a that is narrowed toward the shaft end on the outer peripheral surface, and the inner peripheral surface of the inner seal accommodation hole 250 of the piston member 100 is a tapered surface facing this. Therefore, by screwing the piston member 100 into the linear motion rod 10, the inner seal member 82 and the inner seal accommodation hole 250 are pressed against each other, and as a result, high sealing performance can be secured. In addition, although the case where the piston member 100 side was made into the taper surface was illustrated here, you may make it form a taper surface in the linear motion rod 10 side.

Furthermore, in this embodiment, an annular outer seal fitting portion 210 is formed on the outer peripheral surface of the piston member 100 from the middle to the end surface on the fixing female screw body 30 side. The outer seal fitting portion 210 is formed with a small-diameter surface 201 that continues to the end surface on the fixing male screw body 30 side on the peripheral surface. The small diameter surface 201 has a smaller diameter than the outer peripheral surface, and the piston ring 90 is installed there. The axial dimension of the piston ring 90 is set to be slightly larger than the axial dimension of the small-diameter surface 201 and protrudes from the piston member 100 to the female screw body 30 for fixing. The fixing female screw body 30 is set to have a diameter larger than that of the small-diameter surface 201 and has an outer diameter that is circular. Accordingly, when the fixing female screw body 30 is tightened to the piston member 100 side, the end face of the fixing female screw body 30 comes into contact with the piston ring 90 and the piston ring 90 is fixed. That is, the piston ring 90 is sandwiched between the piston member 100 and the fixing female screw body 30.

As a result, it becomes possible to easily assemble the inner seal member 82 and the piston ring 90 as compared with the conventional case where the seal material is fitted while being elastically deformed. Accordingly, it is not necessary to consider the elastic deformation of the inner seal member 82 and the piston ring 90, so that it is possible to select a material having high rigidity and high wear resistance. Here, the case where the inner seal member 82 has a tapered structure is illustrated, but the inner peripheral surface of the piston ring 90 is tapered

surfaces

90a and 90b as in the application example shown in FIG. 46 to improve the sealing performance. You can also. In this case, the outer

seal fitting portions

210 and 39 are formed on the outer peripheral surface of the piston member 100 and / or the fixing female screw body 30, and the inner peripheral surface of the piston ring 90 is tapered 90a and 90b on each peripheral surface. The taper surfaces 203 and 39a that face each other may be formed. Using the clamping force between the piston member 100 and the fixing female screw body 30, the

tapered surfaces

90a and 90b of the piston ring 90 and the

tapered surfaces

203 and 39a of the piston member 100 and / or the fixing female screw body 30 can be brought into close contact with each other. it can.

In the fourth to ninth embodiments, the case where the engaging male screw body 110 is inserted from the fixing female screw body 30 side toward the piston member 100 side in the relative rotation preventing mechanism 40 is illustrated. However, the present invention is not limited thereto, and it may be inserted from the piston member 100 side toward the engaging male screw body 110 side. Further, in the fourth to ninth embodiments, the case where the relative rotation preventing mechanism 40 is arranged at one place in the circumferential direction is exemplified, but it may be arranged at a plurality of places in the circumferential direction.

Furthermore, in the above-described embodiment, an example in which the piston coupling structure is applied to a hydraulic cylinder has been introduced. However, the present invention is not limited to this, and an appropriate fluid pressure is applied to the piston such as a hydraulic cylinder, an air cylinder, and various dampers. It can be applied to any linear motion system that obtains a desired motion by applying pressure or receiving pressure.

Also, the examples of the present invention are not limited to the above-described embodiments, and it is needless to say that various modifications can be made without departing from the scope of the present invention. For example, the piston member of the present invention is provided with a small hole penetrating the front and back surfaces to form an orifice, and the input to the linear motion rod from the outside is attenuated by the flow of the viscous fluid accommodated inside the tube through the small hole. It can also be set as the structure made to act on.

DESCRIPTION OF SYMBOLS 1 Seal structure 10 Linear motion rod 12 Shaft part 12a Main-body part 12c End part 13 Male thread part 14 First male thread spiral groove 15 Second male thread spiral groove 17 Rod side cooperation area | region 20 Step part 22 Rod side seat part 23 Rod side contact part 23X Male screw side contact area 23Y Male screw side contact area 30 Fixing female screw body 31 Outer peripheral surface 31a of fixing female screw body Flat surface portion 33 of fixing female screw body Second female screw part 40 Relative rotation prevention mechanism 50 Cooperation member (washer, piston )
52 Insertion hole 53 Washer side contact portion 53X First washer side contact region 53Y Second washer side contact region 60 First receiving portion 64 First receiving portion side unevenness 70 Second receiving portion 82 Inner seal member 90 Piston ring ( Outer seal member)
DESCRIPTION OF SYMBOLS 100 Piston member 100a Insertion hole 102 Seat part 104 Screw body side unevenness 105a Seal part 106a (First) Female screw part 106b Piston side cooperation area 108 Female screw side contact part 110 Engaging male screw body 111 Engaging pin 115 Release male screw body 150 Washer 181 Second engagement hole 191 First engagement hole 201 Small diameter surface 203 Tapered surface 210 Outer seal fitting portion 250 Inner seal accommodation hole 300 Piston body C Shaft center (screw shaft)

Claims

A fluid applied to a linear motion system comprising: a piston body that is accommodated in a tube so as to be axially movable; and the linear motion rod that holds the piston body and interlocks with the reciprocating movement of the piston body. A seal structure,
The fluid moves close to the inner peripheral surface in an outer peripheral surface that constitutes at least a part of the piston body and that is inserted into the linearly acting rod and that faces the inner peripheral surface of the tube. A piston member having a seal portion to regulate;
An annular outer seal fitting portion formed on the outer peripheral surface of the piston member, having a smaller diameter than the seal portion, and continuing to any one of a pair of end surfaces facing in the axial direction;
An annular outer seal member that is in contact with the outer seal fitting portion of the piston member;
An outer seal holding member that is disposed in the vicinity of the end surface of the piston member and presses the outer seal member in the axial direction toward the outer seal fitting portion;
Characterized by comprising,
Seal structure of linear motion system.
The outer seal holding member is fixed to an end surface of the piston member,
The seal structure of the linear motion system according to claim 1.
The outer seal holding member is
It has a female screw portion for holding member that is screwed into the male screw portion of the linear motion rod,
The seal structure of the linear motion system according to claim 1.
A first male screw spiral groove and a second male screw spiral groove having different lead angles and / or lead directions are formed in the male thread portion of the linear motion rod,
In the basic hole of the piston member, an internal thread portion for a piston that is screwed with the first external thread spiral groove of the linear motion rod is formed,
The female thread portion for the retaining portion of the outer seal retaining member is screwed with the second male thread spiral groove,
A seal structure for a linear motion system according to claim 3.
The peripheral surface of the outer seal fitting portion is configured to have a tapered shape in which the seal portion side has a large diameter and the end surface side has a small diameter,
A seal structure for a linear motion system according to any one of claims 1 to 4.
The pressing surface for pressing the outer seal member in the outer seal holding member is configured in an annular taper shape having a smaller diameter in the pressing direction.
A seal structure for a linear motion system according to any one of claims 1 to 5.
An annular inner seal member disposed between the linear motion rod and the piston member or the outer seal holding member;
The piston member or the outer seal holding member is
A basic hole into which the linear rod is inserted;
It has a larger diameter than the basic hole, and has an annular inner seal housing hole that continues to any one of a pair of end faces facing in the axial direction of the inserted member,
The inner seal member is in contact with the inner seal accommodation hole,
A seal structure for a linear motion system according to any one of claims 1 to 6.
A stepped portion or a tapered surface that engages with the inner seal member in the axial direction is formed on the outer peripheral surface of the linear motion rod.
A seal structure for a linear motion system according to claim 7.
The peripheral surface of the inner seal accommodation hole has a taper structure in which the basic hole side has a small diameter and the end surface side has a large diameter,
A seal structure for a linear motion system according to claim 7 or 8.
In the shaft portion having the male screw portion, the linear motion rod is formed with a rod side cooperation region having a non-circular cross section when viewed from the axial direction,
In the insertion hole, the piston member is formed with a female screw part that is screwed with the male screw part, and a piston side cooperation region that has a non-circular cross section when viewed from the axial direction,
The rod side cooperation region and the piston side cooperation region are structured to engage with each other in the circumferential direction while allowing relative rotation by an external force.
A seal structure for a linear motion system according to any one of claims 1 to 9.
Comprising at least a part of the piston body, and a cooperating member having an insertion hole into which the linear rod is inserted;
In the shaft portion having the male screw portion, the linear motion rod is formed with a rod side cooperation region having a non-circular cross section when viewed from the axial direction,
In the insertion hole of one of the piston member and the linkage member, a piston side linkage region that engages in the circumferential direction with the rod side linkage region is formed by making the inner circumference non-circular,
In the other insertion hole of the piston member and the linkage member, a female thread portion for piston that is screwed with the male thread portion of the linear motion rod is formed,
Between the piston member and the cooperation member, a relative rotation prevention mechanism in which both engage in the circumferential direction is arranged,
A seal structure for a linear motion system according to any one of claims 1 to 3.
The linkage member also serves as the outer seal holding member,
The seal structure according to claim 11.
The basic hole of the piston member is formed with a female screw portion that is screwed with a male screw portion of the linear motion rod,
A seal structure for a linear motion system according to any one of claims 1 to 3.
A fluid applied to a linear motion system comprising: a piston body that is accommodated in a tube so as to be axially movable; and the linear motion rod that holds the piston body and interlocks with the reciprocating movement of the piston body. A seal structure,
An inserted member that constitutes at least a part of the piston body and has an insertion hole into which the linear rod is inserted;
An annular inner seal member disposed between the linear motion rod and the inserted member,
The insertion hole of the inserted member is
A basic hole into which the linear rod is inserted;
It has a larger diameter than the basic hole, and has an annular inner seal housing hole that continues to any one of a pair of end faces facing in the axial direction of the inserted member,
The inner seal member is in contact with the inner seal accommodation hole,
Seal structure of linear motion system.
A stepped portion or a tapered surface that engages with the inner seal member in the axial direction is formed on the outer peripheral surface of the linear motion rod.
The seal structure of the linear motion system according to claim 14.
The peripheral surface of the inner seal accommodation hole has a taper structure in which the basic hole side has a small diameter and the end surface side has a large diameter,
The seal structure of the linear motion system according to claim 14 or 15.
The inserted member is a piston member having a seal portion that restricts movement of the fluid in the vicinity of the inner peripheral surface on the outer peripheral surface facing the inner peripheral surface of the tube;
The piston member is
An annular outer seal fitting portion formed on the outer peripheral surface, having a smaller diameter than the seal portion, and continuing to any one of a pair of end surfaces facing in the axial direction;
An annular outer seal member that is in contact with the outer seal fitting portion of the piston member;
An outer seal holding member that is disposed in the vicinity of the end surface of the piston member and presses the outer seal member in the axial direction toward the outer seal fitting portion;
Characterized by comprising,
The linear structure seal structure according to any one of claims 14 to 16.
The outer seal holding member is fixed to an end surface of the piston member,
The seal structure of the linear motion system according to claim 17.
The outer seal holding member is
It has a female screw portion for holding member that is screwed into the male screw portion of the linear motion rod,
The seal structure of the linear motion system according to claim 17.
A first male screw spiral groove and a second male screw spiral groove having different lead angles and / or lead directions are formed in the male thread portion of the linear motion rod,
In the basic hole of the piston member, an internal thread portion for a piston that is screwed with the first external thread spiral groove of the linear motion rod is formed,
The female thread portion for the retaining portion of the outer seal retaining member is screwed with the second male thread spiral groove,
A seal structure for a linear motion system according to claim 19.
Comprising at least a part of the piston body, and a second inserted member having an insertion hole into which the linear rod is inserted;
A first male screw spiral groove and a second male screw spiral groove having different lead angles and / or lead directions are formed in the male thread portion of the linear motion rod,
The basic hole of the member to be inserted is formed with a female screw portion that is screwed into the first male screw spiral groove of the linear motion rod,
The insertion hole of the second inserted member is formed with a female screw portion that is screwed with the second male screw spiral groove of the linear motion rod.
The linear structure seal structure according to any one of claims 14 to 16.
The peripheral surface of the outer seal fitting portion has a taper structure in which the seal portion side has a large diameter and the end surface side has a small diameter,
A seal structure for a linear motion system according to any one of claims 14 to 21.
In the shaft portion having the male screw portion, the linear motion rod is formed with a rod side cooperation region having a non-circular cross section when viewed from the axial direction,
In the insertion hole, the inserted member is formed with a female screw part that is screwed with the male screw part, and a piston side cooperation region that has a non-circular cross section when viewed from the axial direction,
The rod side cooperation region and the piston side cooperation region are structured to engage with each other in the circumferential direction while allowing relative rotation by an external force.
The linear structure seal structure according to any one of claims 14 to 22.
Comprising at least a part of the piston body, and a second inserted member having an insertion hole into which the linear rod is inserted;
In the shaft portion having the male screw portion, the linear motion rod is formed with a rod side cooperation region having a non-circular cross section when viewed from the axial direction,
In the insertion hole of one of the inserted member and the second inserted member, a piston side cooperation region that is engaged in the circumferential direction with the rod side cooperation region is formed by forming an inner periphery in a non-circular shape,
The other insertion hole of the inserted member and the second inserted member is formed with a female screw portion that is screwed with the male screw portion of the linear motion rod,
Between the inserted member and the second inserted member, a relative rotation preventing mechanism that engages both in the circumferential direction is arranged,
The linear structure seal structure according to any one of claims 14 to 16.
The basic hole of the member to be inserted is formed with a female screw portion that is screwed with a male screw portion of the linear motion rod,
A seal structure for a linear motion system according to any one of claims 14 to 18.
A piston member which is accommodated in the tube so as to be movable in the axial direction, is fixed to the linear motion rod in the tube, receives the pressure of the fluid, and transmits the fluid to the linear motion rod;
A pressure receiving surface that is formed on at least one of a pair of end faces facing in the axial direction and receives the pressure of the fluid;
An insertion hole into which the linear motion rod is inserted;
A seal portion that is formed on the outer peripheral surface facing the inner peripheral surface of the tube and restricts the movement of the fluid in the vicinity of the inner peripheral surface;
An annular outer seal fitting portion formed on the outer peripheral surface, having a smaller diameter than the seal portion, and continuing to the end surface;
The outer seal fitting portion is configured so that an annular outer seal member can be arranged.
Piston member.
The peripheral surface of the outer seal fitting portion has a taper structure in which the seal portion side has a large diameter and the end surface side has a small diameter,
The piston member according to claim 26.
The insertion hole is
A basic hole into which the linear rod is inserted;
It has a larger diameter than the basic hole, and has an annular inner seal housing hole that continues to the end surface,
An annular inner seal member is configured to be disposed in the inner seal accommodation hole.
The piston member according to claim 26 or 27.
The peripheral surface of the inner seal accommodation hole has a taper structure in which the basic hole side has a small diameter and the end surface side has a large diameter,
The piston member according to claim 28.
The insertion hole is formed with a female screw part that is screwed with a male screw part of the linear motion rod,
The piston member according to any one of claims 26 to 29.