JP2018066471A - Fluid pressure cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid pressure cylinder which can prevent rotation of a piston rod with a simple structure.SOLUTION: A fluid pressure cylinder 10 has a cylinder body 12, a piston 68 driven by a fluid pressure, and a piston rod 18 connected with the piston. A connection member 20 is connected to an end part of the piston rod protruding from the cylinder body, and multiple guide members 22 are erected on an end surface of the cylinder body. The connection member has at least one side surface which is parallel to an axis of the piston rod. Side surfaces of the guide members contact with one of the side surfaces of the connection member.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fluid pressure cylinder, and more particularly to a fluid pressure cylinder including a piston rod rotation prevention mechanism.

  2. Description of the Related Art Conventionally, a fluid pressure cylinder that prevents rotation of a piston rod by arranging two guide rods in parallel with the piston rod and connecting the piston rod and the guide rod with a connecting plate is known. (See Patent Document 1).

  In addition, a block-shaped connecting member is connected to the projecting end of the piston rod, and a connecting pin supported by the supporting recess of the connecting member is inserted into an insertion recess formed on the end surface of the cylinder body to rotate the connecting member. A fluid pressure cylinder is known which is regulated (see Patent Document 2). In this fluid pressure cylinder, a plurality of insertion recesses are arranged around the central axis of the piston, and the coupling pin can be selectively inserted into one of the insertion recesses, thereby changing the posture of the connecting member. It has become.

Japanese Patent Laid-Open No. 9-229016 Japanese Patent No. 5948278

  However, in the fluid pressure cylinder of Patent Document 1, it is inevitable that the entire apparatus increases in size as the guide rods are arranged.

  Moreover, in the fluid pressure cylinder of patent document 2, it is necessary to support a coupling pin in the support recessed part of a connection member, and a structure is complicated.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a fluid pressure cylinder that can prevent the rotation of the piston rod with a simple configuration.

  The fluid pressure cylinder according to the present invention has a cylinder body, a piston driven by fluid pressure, a piston rod connected to the piston, and a connecting member is connected to an end of the piston rod protruding from the cylinder body, A plurality of guide members are erected on the end surface of the cylinder body, the connecting member has at least one side surface parallel to the axis of the piston rod, and the side surfaces of the plurality of guide members can contact one of the side surfaces of the connecting member It is characterized by being.

  According to the fluid pressure cylinder described above, the piston rod can be prevented from rotating with a simple structure by bringing a plurality of guide members standing on the end face of the cylinder body into contact with the side surface of the connecting member.

  In the above fluid pressure cylinder, it is preferable that the guide member is detachably provided on the cylinder body. According to this, the attitude | position of the connection member with respect to a cylinder main body can be changed.

  Further, the connecting member is preferably formed in a prismatic shape whose cross section perpendicular to the axis of the piston rod is a polygon such as a square. According to this, the attitude | position of the connection member with respect to a cylinder main body can be changed easily.

  Further, an intermediate driving body driven by fluid pressure may be slidably provided inside the cylinder body, and the piston may be slidably provided inside the intermediate driving body. According to this, the displacement amount of the piston with respect to the cylinder body can be increased as much as possible. In this case, the end located on the opposite side of the connecting member of the intermediate drive body can be protruded and retracted from the cylinder body, and the end of the piston rod opposite to the connecting member can be protruded and retracted from the intermediate drive body and the cylinder body. It is good also as a certain structure.

  Furthermore, it is particularly beneficial when a pipe is connected to the side surface of the connecting member. That is, since the connecting member integral with the piston rod is prevented from rotating around the axis of the piston rod, the pipe connected to the connecting member is also held at a fixed position.

  In the fluid pressure cylinder according to the present invention, a plurality of guide members standing on the end surface of the cylinder body are brought into contact with the side surface of the connecting member, and the rotation of the piston rod can be prevented with a simple configuration.

It is a perspective view of a fluid pressure cylinder concerning an embodiment of the present invention. It is sectional drawing along the II-II line of the fluid pressure cylinder shown in FIG. It is the top view which looked at the fluid pressure cylinder shown in FIG. 1 from upper direction. It is the top view which looked at the fluid pressure cylinder shown in FIG. 1 from the downward direction. FIG. 3 is a cross-sectional view when the piston rod is displaced upward in the fluid pressure cylinder shown in FIG. 2. FIG. 6A is a diagram illustrating a first modification example regarding the cross-sectional shape of the connecting member and the arrangement of the insertion holes. 6B and 6C are diagrams illustrating a second modification example regarding the cross-sectional shape of the connecting member and the arrangement of the insertion holes.

  Hereinafter, preferred embodiments of a fluid pressure cylinder according to the present invention will be described with reference to the accompanying drawings. Hereinafter, “upper” or “lower” refers to the vertical direction in FIGS. 2 and 5.

  The fluid pressure cylinder 10 according to the embodiment of the present invention is used for the purpose of discharging or filling the gas in the semiconductor wafer storage container. As shown in FIGS. 1 and 2, the fluid pressure cylinder 10 includes a cylinder body 12, a cover body 14, an intermediate drive body 16, a piston rod 18, a connecting member 20, and a guide member 22.

  The cylinder main body 12 includes a rectangular parallelepiped main body portion 24 having a rectangular cross section perpendicular to the axial direction (vertical direction), and a mounting portion 26 formed integrally on a side surface of the main body portion 24. A drive body insertion hole having a circular cross section penetrating in the vertical direction is formed. The cylinder body 12 is attached to a base (not shown) at the attachment portion 26. The driver insertion hole has an enlarged diameter step portion 30 formed on the upper end opening side, a large diameter portion 32 following the enlarged diameter step portion 30, and a small diameter portion 34 following the large diameter portion 32. A first packing 36 is attached to the enlarged diameter step portion 30, and a second packing 38 is attached to the small diameter portion 34 via an annular groove.

  A cover body 14 is attached to the upper end of the cylinder body 12 by a plurality of fixtures 40. A cross section perpendicular to the axial direction (vertical direction) of the cover body 14 is the same shape as the cross sectional shape of the cylinder body 12. Inside the cover body 14, a drive body end portion insertion hole having a circular cross section penetrating in the vertical direction is formed, and a flange 44 projecting inward is provided at the upper end of the drive body end portion insertion hole. The diameter of the driving body end portion insertion hole is substantially the same as or slightly smaller than the diameter of the large diameter portion 32 of the driving body insertion hole formed in the cylinder body 12.

  The intermediate driving body 16 is a cylindrical member having a circular cross section, and a piston rod insertion hole having a circular cross section penetrating in the vertical direction is formed in the intermediate driving body 16. The outer peripheral surface of the intermediate driving body 16 has a second outer diameter portion 50 on the upper side of the first outer diameter portion 48 with the first outer diameter portion 48 having the largest outer diameter interposed therebetween. A third outer diameter portion 52 and a fourth outer diameter portion 54 having a smaller diameter than the third outer diameter portion 52 are provided on the lower side. The diameter of the second outer diameter portion 50 is substantially the same as or slightly smaller than the inner diameter of the flange 44 of the cover body 14. The piston rod insertion hole has a screw portion 56 formed on the upper end opening side, a large diameter portion 58 following the screw portion 56, and a small diameter portion 60 following the large diameter portion 58. The small diameter portion 60 has an annular groove. The third packing 62 is attached through the gap.

  The intermediate drive body 16 is inserted through a drive body insertion hole formed in the cylinder body 12 and a drive body end portion insertion hole formed in the cover body 14 so as to be movable in the axial direction (vertical direction). The first packing 36 contacts the first outer diameter portion 48 of the intermediate driving body 16, and the second packing 38 contacts the fourth outer diameter portion 54 of the intermediate driving body 16. The large diameter portion 32 of the driving body insertion hole, the boundary wall of the large diameter portion 32 and the small diameter portion 34 of the driving body insertion hole, and the boundary wall of the first outer diameter portion 48 and the third outer diameter portion 52 of the intermediate driving body 16 The first pressure chamber 64 is defined by the outer peripheral surface up to the fourth outer diameter portion 54. The cylinder body 12 is provided with a port 66 for supplying and discharging the pressure fluid to and from the first pressure chamber 64. The port 66 is selected as a pressure fluid supply source and a negative pressure generation source (not shown) via a pipe and a switching valve (not shown). Connected.

  The intermediate drive body 16 is restricted from moving upward by the boundary wall between the first outer diameter portion 48 and the second outer diameter portion 50 coming into contact with the flange 44 of the cover body 14 (see FIG. 5), and the third outer The boundary wall between the diameter portion 52 and the fourth outer diameter portion 54 abuts against the boundary wall between the large diameter portion 32 and the small diameter portion 34 of the driving body insertion hole formed in the cylinder body 12, so that downward movement is restricted. (See FIG. 2). The axial length of the intermediate drive body 16 is equal to the sum of the axial length of the cylinder body 12 and the axial length of the cover body 14. In a state where the boundary wall between the third outer diameter portion 52 and the fourth outer diameter portion 54 of the intermediate driving body 16 is in contact with the boundary wall between the large diameter portion 32 and the small diameter portion 34 of the driving body insertion hole, the intermediate driving body 16 The upper surface and the upper surface of the cover body 14 are flush with each other, and the lower surface of the intermediate driver 16 and the lower surface of the cylinder body 12 are flush with each other.

  The piston rod 18 is inserted into a piston rod insertion hole formed in the intermediate drive body 16 so as to be movable in the axial direction, and a piston portion that is in sliding contact with the large diameter portion 58 of the piston rod insertion hole at a position near the center of the piston rod 18. 68 (piston) is provided. A piston packing 70 is mounted on the outer peripheral surface of the piston portion 68 via an annular groove, and a stepped portion 72 is formed on the lower end side outer peripheral surface of the piston portion 68. The third packing 62 attached to the small diameter portion 60 of the piston rod insertion hole comes into contact with the outer peripheral surface of the piston rod 18 located below the piston portion 68. The second pressure chamber 74 is formed by the large diameter portion 58 of the piston rod insertion hole, the boundary wall between the large diameter portion 58 and the small diameter portion 60, the stepped portion 72 of the piston portion 68, the lower end surface of the piston portion 68, and the outer peripheral surface of the piston rod 18. Defined. The intermediate drive body 16 is formed with a fluid conduction hole 76 that traverses from the third outer diameter portion 52 to the large diameter portion 58 of the piston rod insertion hole, and the second pressure chamber 74 is connected to the first pressure chamber via the fluid conduction hole 76. It communicates with the pressure chamber 64. A through hole 78 penetrating in the vertical direction is formed in the piston rod 18.

  The connecting member 20 connected to the lower end of the piston rod 18 is formed in a rectangular parallelepiped shape with a cross section perpendicular to the axial direction (vertical direction). Inside the connecting member 20, there are formed a vertical hole 80 whose upper end opens at the center of the upper surface of the connecting member 20, and a horizontal hole 82 that connects to the vertical hole 80 and opens on one side of the connecting member 20. The vertical hole 80 has a female thread portion, and the lower end of the piston rod 18 is screwed into the vertical hole 80 and fixed. The opening of the horizontal hole 82 is connected to a negative pressure generation source (not shown) through a pipe. The lower end of the through hole 78 of the piston rod 18 communicates with the vertical hole 80 of the connecting member 20, and the upper end of the through hole 78 serves as a gas inlet for discharging gas in a semiconductor wafer storage container (not shown). As shown in FIG. 2, the connecting member 20 is disposed in a posture in which the side surface where the lateral hole 82 opens is located on the side opposite to the mounting portion 26 of the cylinder body 12. In addition, in FIG. 4, the pipe joint provided in the opening part of the horizontal hole 82 is shown with the virtual line.

  The piston rod 18 is restricted from moving upward by the upper surface of the connecting member 20 coming into contact with the lower surface of the cylinder body 12 (see FIG. 5), and the piston rod 68 is formed in the intermediate drive body 16. The downward movement is regulated by contacting the boundary wall between the large-diameter portion 58 and the small-diameter portion 60 (see FIG. 2). When the piston portion 68 is in contact with the boundary wall between the large diameter portion 58 and the small diameter portion 60 of the piston rod insertion hole, the upper surface of the piston rod 18 is flush with the upper surface of the intermediate driving body 16.

  As shown in FIGS. 2 and 4, two rod-shaped guide members 22 are erected downward on the lower surface of the cylinder body 12. A set of insertion holes 84 having a predetermined depth is formed on the lower surface of the cylinder body 12, and a fixing hole 86 reaching the insertion hole 84 from the side surface of the cylinder body 12 is formed. The end of the guide member 22 is inserted into the insertion hole 84, the set screw 88 is inserted and screwed into the fixing hole 86, and the tip of the set screw 88 is pressed against the side surface of the guide member 22. It is fixed to the main body 12. As shown in FIG. 4, the two guide members 22 are adjacent corners of the rectangular lower surface of the cylinder body 12 and are disposed at an equal distance from the center of the connecting member 20, that is, the axis of the piston rod 18. The The distance between the two guide members 22 is slightly shorter than one side of the square cross section of the connecting member 20, and the two guide members 22 abut against the same side surface of the connecting member 20.

  The length of the portion where the guide member 22 protrudes from the lower surface of the cylinder body 12 is substantially the same as the length of the connecting member 20 in the vertical direction. When the piston rod 18 is located at the uppermost position, that is, when the upper surface of the connecting member 20 is in contact with the lower surface of the cylinder body 12, the two guide members 22 extend over substantially the entire length of the portion protruding from the lower surface of the cylinder body 12. Then, it contacts one side surface of the connecting member 20 (see FIG. 5). Further, when the piston rod 18 is located at the lowest position, that is, the lower surface of the intermediate driving body 16 and the lower surface of the cylinder body 12 are flush with each other, and the piston rod 18 protrudes downward from the intermediate driving body 16. In this state, the two guide members 22 come into contact with one side surface of the connecting member 20 at the tip portions (see FIG. 2). That is, the two guide members 22 come into contact with one side surface of the connecting member 20 in the entire stroke range of the piston, and the connecting member 20 integrated with the piston rod 18 is prevented from rotating around the axis of the piston rod 18. . The intermediate driver 16 is rotatable with respect to the cylinder body 12.

  The fluid pressure cylinder 10 according to the present embodiment is basically configured as described above, and the operation thereof will be described below with reference to FIGS. 2 and 5. Here, the state where the piston rod 18 is located at the lowest position as shown in FIG.

  In this initial state, when the switching valve is switched to connect the port 66 to the pressure fluid supply source, the pressure fluid is introduced into the first pressure chamber 64 and part of the pressure fluid introduced into the first pressure chamber 64 is The fluid is introduced into the second pressure chamber 74 through the fluid conduction hole 76. As the pressure fluid is introduced into the first pressure chamber 64, the intermediate driver 16 is displaced upward with respect to the cylinder body 12, and as the pressure fluid is introduced into the second pressure chamber 74, the piston rod 18 is displaced upward with respect to the intermediate driver 16.

  At this time, the displacement amount of the piston rod 18 is the sum of the displacement amount of the intermediate drive body 16 relative to the cylinder body 12 and the displacement amount of the piston rod 18 relative to the intermediate drive body 16. Therefore, the displacement amount of the piston rod 18 can be increased as much as possible.

  As shown in FIG. 5, the intermediate drive body 16 is displaced upward until the boundary wall between the first outer diameter portion 48 and the second outer diameter portion 50 contacts the flange 44 of the cover body 14, and the piston rod 18 is displaced upward until the upper surface of the connecting member 20 contacts the lower surface of the cylinder body 12.

  After the predetermined operation is completed, when the switching valve is switched to connect the port 66 to the negative pressure generating source, the pressure fluid in the second pressure chamber 74 moves to the first pressure chamber 64 and the first pressure chamber 64 Pressure fluid is discharged through port 66. Then, the piston rod 18 and the intermediate driving body 16 are displaced downward to return to the initial state.

  The two guide members 22 erected on the lower surface of the cylinder body 12 are always in contact with one side surface of the connecting member 20 regardless of the displacement of the piston rod 18 with respect to the cylinder body 12. Therefore, the connecting member 20 to which the pipe is connected can be reliably prevented from rotating around the axis of the piston rod 18.

  When it is desired to change the posture of the connecting member 20 with respect to the cylinder body 12, the set screw 88 is loosened and the two guide members 22 are pulled downward along the side surface of the cylinder body 12. Thereby, the piston rod 18 and the connecting member 20 can be rotated around the axis of the piston rod 18. Then, after rotating the connecting member 20 by 90 degrees, 180 degrees, or 270 degrees, the two guide members 22 are inserted into the insertion holes 84 along the side surfaces different from the above of the connecting member 20. When the fixing member 88 is fixed again, the connecting member 20 maintains the changed posture.

  As described above, when the cross section of the connecting member 20 is square, the posture of the connecting member 20 can be changed every 90 degrees. 6A to 6C show examples in which the cross-sectional shape of the connecting member 20 and the position of the insertion hole 84 are changed. These figures are plan views of the fluid pressure cylinder as seen from below, as in FIG.

  FIG. 6A is an example in which the cross-sectional shape of the connecting member 20a is a regular hexagon, and a set of insertion holes 84a are arranged so that the two guide members 22 abut one of the six side surfaces of the connecting member 20a. The piston rod 18 is provided at the exact center of the connecting member 20a. In this example, the posture of the connecting member 20 can be changed every 60 degrees.

  6B and 6C, the cross-section of the connecting member 20b is rectangular, and a set of insertion holes 84b are arranged so that the two guide members 22 abut on the side surface of the connecting member 20b corresponding to the long side of the rectangle. In this example, a set of insertion holes 84c are arranged so that the two guide members 22 abut on the side surface of the connecting member 20b corresponding to the short side of the rectangle. The piston rod 18 is provided in the exact center of the connecting member 20b. The distance of the insertion hole 84b from the axis of the piston rod 18 is substantially equal to the distance of the insertion hole 84c from the axis of the piston rod 18. As shown in FIG. 6B, when the guide member 22 is inserted into the pair of insertion holes 84b, the two guide members 22 can be brought into contact with the side surface of the connecting member 20b corresponding to the long side of the rectangle. As shown in FIG. 6C, when the guide member 22 is inserted into the pair of insertion holes 84c, the two guide members 22 can be brought into contact with the side surface of the connecting member 20b corresponding to the rectangular short side. it can. In this example, the attitude of the connecting member 20 can be changed every 90 degrees. For convenience, the guide member 22 is hatched in FIGS. 6B and 6C.

  According to the fluid pressure cylinder 10 according to the present embodiment, the piston rod 18 can be configured with a simple configuration by bringing the two guide members 22 erected on the end surface of the cylinder body 12 into contact with one side surface of the connecting member 20. Can be prevented from rotating.

  Further, since the two guide members 22 are detachably provided on the cylinder body 12, the posture of the connecting member 20 with respect to the cylinder body 12 can be changed.

  In this embodiment, the guide member is brought into contact with the side surface of the connecting member without a substantial gap. However, the guide member is opposed to the side surface of the connecting member with a slight gap so as to prevent the piston rod from rotating more than a predetermined amount. It may be.

  The fluid pressure cylinder according to the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Fluid pressure cylinder 12 ... Cylinder main body 16 ... Intermediate drive body 18 ... Piston rod 20 ... Connection member 22 ... Guide member 68 ... Piston part (piston) 78 ... Through-hole

Claims (7)

A fluid pressure cylinder having a cylinder body, a piston driven by fluid pressure, and a piston rod coupled to the piston,
A connecting member is connected to an end portion of the piston rod protruding from the cylinder body, and a plurality of guide members are erected on an end surface of the cylinder body, and the connecting member is at least one side surface parallel to the axis of the piston rod. The fluid pressure cylinder is characterized in that side surfaces of the plurality of guide members can contact one of the side surfaces of the connecting member. The fluid pressure cylinder according to claim 1, wherein
The fluid pressure cylinder, wherein the guide member is detachably provided on the cylinder body. The fluid pressure cylinder according to claim 2,
The fluid pressure cylinder, wherein the connecting member is formed in a prismatic shape having a polygonal cross section perpendicular to the axis of the piston rod. The fluid pressure cylinder according to claim 3,
The fluid pressure cylinder, wherein the connecting member has a square cross section perpendicular to the axis of the piston rod. The fluid pressure cylinder according to claim 1, wherein
An intermediate driving body driven by fluid pressure is slidably provided inside the cylinder body, and the piston is slidably provided inside the intermediate driving body. The fluid pressure cylinder according to claim 5,
An end portion of the intermediate drive body that is located on the opposite side of the connecting member can be protruded and retracted from the cylinder body, and an end portion of the piston rod that is on the opposite side of the connection member is the intermediate drive body and the cylinder body. A fluid pressure cylinder characterized by being able to move in and out. The fluid pressure cylinder according to claim 1, wherein
A fluid pressure cylinder, wherein a pipe is connected to a side surface of the connecting member.

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