JPH0271911A - Chuck device - Google Patents

Abstract

PURPOSE:To especially support a weak portion through the rigidity of a body and act it as a compressive stress so as to achieve a strong chucking force by setting the width of a slot groove to be narrower than the breakage ending portion of zigzag lines on the outer periphery of a plunger. CONSTITUTION:The force applied on the projecting part 12 of a jaw 2, which is generated in holding a workpiece, is separated into surface pressure load and bending load components through the acting force of the plunger 4. The surface pressure load and the bending load are set to be received by a wedge member 50 and a reinforcing member 60, respectively. Using such a method as supporting the component forces, a jaw part V forming the T-shaped wedge groove of the plunger 4 is set to receive only a cantile load. In this case, the width A of the slot groove 11 is set to be narrower than the outer periphery breakage ending portion for improving the strength of the jaw part V.

Description

[Detailed description of the invention]

The present invention relates to a chuck used in machine tools, and even in the high rotation range due to the recent trend towards high speed rotation.
This invention relates to a chuck that has the ability to provide powerful gripping force and high gripping accuracy. [Prior art 1] A conventional solid chuck structure is provided with a meshing means for meshing with a plunger on the inner part of the jaw corresponding to the radially inner part of the body, as shown in FIGS. 1 to 4. It is. Furthermore, the hollow chuck structure is provided with an engaging means that engages with the plunger at the rear inner part of the jaw, which corresponds to the rear part in the axial direction of the body and the inner part in the radial direction. Figures 1 to 4 [ii! It is as shown below. However, in both the former and latter engaging means, there is a significant difference between the strength of the engaging part on the plunger side and the engaging part strength on the plunger side, and it is difficult to eliminate this mechanical strength difference due to structural limitations. It was said to be difficult. Moreover, this dynamic strength difference tends to further expand as the gripping force increases, which is a problem that is particularly important in high rotational speed ranges. (Problems to be Solved by the Invention) The present invention successfully solves the drawbacks of the conventional chuck, and by investigating the structure of the engaging means from the structural and mechanical aspects, the jaw and body can be formed into a rational shape. The main objective is to obtain a light tray with a strong plunger with high rigidity and extremely low distortion. The present invention also focuses on obtaining a body that is not affected by rigidity.

[Means for Solving the Problems 1] However, the present invention has a special body structure, a special jaw structure, and a special plunger structure as described below, and also dynamically rationalizes the engagement relationship between these two. It has a structure with a flexible combination, and its features include a protrusion with a T-shaped cut end at the rear of the jaw, and the protrusion has a wedge member and a reinforcing member perpendicular to the wedge member. and the reinforcing member is shaped to include a portion accommodated in a slot groove formed in the body. In particular, the body has slot grooves. The point of view of reinforcing the reinforcing member by accommodating the reinforcing member in the slot groove is completely new, and is one of the important structural requirements in that it is highly effective in obtaining a strong gripping force as described later. be. (Function) The function will be explained using Fig. 7 and Fig. 8. The acting force acting on the protrusion 12 at the rear of the machine generated by grasping the workpiece is 1 bending load component force and surface pressure load. The bending load is mainly applied to the reinforcing member 6.
0, and the surface pressure load is assumed to be carried mostly by the wedge member 50. And in order to fully bear the increase in bending load that increases with 1 force grip. The reinforcing member 60 is shaped to include a portion accommodated in the slot groove 11, thereby completely reinforcing the reinforcing member 60. Embodiment 1 An example of the chuck according to the present invention will be described in detail with reference to FIGS. 5 to 9. Fig. 5 is a vertical cross-sectional view of the three-jaw chuck, Fig. 6 is an enlarged partial view of the body 1 seen from an oblique direction, Fig. 7 is a perspective view of the master jaw 2, and Fig. @8 is the Y of Fig. 5. -Y' line cut enlarged view, FIG. 9 is a perspective view of the plunger 4. As shown in FIG. 6, the body 1 has an arrow Z direction. That is, from the inside to the outside in the radial direction, guide grooves 10 for fitting into the master jaw 2 are provided equally in three directions (only one direction is shown), as well as the groove bottom of the guide groove 1o. is provided with a slot groove 11 having a width A and a constant length K which is narrower than the groove width and leaves an appropriate amount of wall thickness W toward the outside in the radial direction. A part of the reinforcing member 60 constituting the protruding portion 12 of the master jacket 2 shown is accommodated therein. In this case, the slot groove width A is made approximately equal to the width B of the outer circumferential groove of the wedge portion of the plunger 4 as shown in FIG. On the other hand, the gap between the outer circumferential surface G and the inner circumferential surface F is preferably set to a minimum value within the range in which the plunger 4 can slide in the axial direction to maintain grasping accuracy. It is something to do. In the embodiments described above, the idea to make the gripping force stronger than ever is to increase the mechanical rigidity and strength of the protrusion 12 provided on the rear inner portion of the master jaw 2. A specific example of this will be explained based on FIG. 7. As shown in FIG. Wedge part 1 which is a protruding part towards the rear inward side
2 is a provision. The wedge portion 12 includes a wedge member 50 that generates a wedge action when meshing with the wedge groove 5 of the plunger 4 shown in FIG. The wedge member 50 mainly bears the surface pressure load during meshing, and the reinforcing member 60 mainly bears the bending load during meshing. However, what is the required shape of the reinforcing member 60? Its section modulus Z is effective for bending load during meshing.
is large, that is, to explain it in terms of a mechanical equation, when the width is C and the height is L, Z = CL''/6
(C and L are shown in the seventh diagram) by increasing L. In this embodiment, the slot groove 11 is formed on the outer side in the radial direction of the body 1, and the reinforcing member 60 has a shape that includes a portion accommodated in the slot groove 11, so that the above-mentioned dimensions can be made extremely large. This is something that has been devised. At this time, the shape of the outer end surface of the reinforcing member 60 is not made into a straight line as shown in FIG. Apart from the fact that the processing is repeated, it is preferable to make it similar to a mechanically reasonable bending moment diagram curve. On the other hand, the shape of the wedge hook piece 10 according to the invention described in JP-A-55-106707 is formed to have a convex cross section with a wedge surface 10a and a ridge-like ridge 10b. By increasing the radial thickness of 10, the above-mentioned bending load is borne. However, since the base of the ridge [Ob] which is most effective in bearing the bending load is slightly reduced, a strong gripping force cannot be obtained. Therefore, when compared with the master jaw shown in FIG. 7 relating to this embodiment, the bending load is small in terms of heat insulation. Another idea to make the gripping force stronger than ever before will be explained based on the structure of the plunger. First, the plunger structure of a conventional chuck will be explained in detail with reference to FIGS. 1 to 4. FIG. 1 is a vertical sectional view of the top part of the three-jaw chuck, and the first
As shown in FIG. 5, a radial guide groove 10' divided into three equal parts is provided in the radial direction of the body 1', and a master jaw 2' shown in the second figure is slidably inserted into the guide groove 10'. and,
The front of master unit 2' (front R and S of body 1')
A top jaw 3' is fixed to the body 1' by a bolt (not shown), and a plunger 4' is fitted into a hole at the center of the body 1' so as to be freely slidable in the axial direction. As shown in FIG. 3, wedge grooves 5' are provided on the outer periphery of the plunger 4' equally in three directions (only one direction is shown). It meshes with part 2'a. Details of the meshing state are shown in FIG. 4, which is an enlarged view taken along line xx' in FIG. 1. A chuck having a structure in which the inner part of the jaw is provided with a meshing means has the following operational drawbacks. When the top jaw 3' is operated to grasp the outer diameter of the workpiece (not shown), a force indicated by arrow P acts radially outward on the wedge portion 2'a of the master jaw 2'. Due to the action of this direction P, a bending moment M acts on the jaw portion 4'b of the T-shaped wedge groove 4'a of the plunger 4' in the direction of the arrow, with the reference point Qtt at which the contact with the hole of the body l' separates. However, as the acting force P increases further, the portion receives stress concentration and damage progresses as seen in the zigzag uA6. Naturally, if the part Q to be separated is not used as the starting point, the damage of the zigzag line 6 will progress in the 45 degree direction from the weakest notch part of the T-shaped wedge groove 4'a. In contrast to the conventional chuck structure mentioned above, the one of this embodiment has the eighth
As shown in the figure, the structure is such that the outer circumferential surface G of the jaw part of the plunger 4 is supported by the inner circumferential surface F of the hole in the body 1 to form a bearing surface, and the zigzag line 6 is This completely prevents damage caused by The wedge portion of the plunger 4 in this embodiment is as follows. As shown in FIG. 9, it is preferable that the wedge groove 5 is formed into a circular arc up to the edge thereof so as to be in sufficient contact with the inner circumferential surface F of the hole at the center of the body, in view of the formation of the bearing surface described above. Even if a part of this circular arc is cut due to the meshing relationship with the seven-stage jaw 2, the cutting i1H is as shown in FIG. If the width is made smaller than that of the master wheel 2, the same effect of the bearing surface can be obtained. (Function 1) The present embodiment is constructed as described above.1 When the cylinder (not shown) is operated and the outer diameter of the workpiece is grasped by the top jaw 3, a force in the radial direction is applied to the wedge portion 12 of the master jaw 2. The acting force is the acting force (surface pressure load) that suppresses and destroys the face value T of the wedge 5 of the plunger 4, and the wedge part 12 of the master jaw 2.
It is divided into the acting force (bending load) that bends and breaks. Considering this with respect to the strength of the master joint 2, the mechanical strength of the wedge member 50 is sufficient as long as it has a shape with sufficient dimensions to withstand a surface pressure load of 1°σI, and the mechanical strength of the reinforcing member 60 is The shape may have sufficient dimensions to withstand the bending load. The reinforcing member 60 constituting the wedge portion 12 of this embodiment is
Body 1 slot I#! 11, it is possible to obtain a considerably large section modulus Z, and it can sufficiently withstand excessive bending loads. On the other hand, when considering the force acting on the plunger 4, the shape of the plunger 4 has a size sufficient to absorb the above-mentioned surface pressure load at the face T of the wedge groove 5. However, when the load is further increased, the jaw portion of the face face itself receives a bending moment M in the direction of the arrow as shown in FIG. 4, and bends outward in the radial direction. In such a case, the bearing surface is formed by supporting the outer circumferential surface G of the jaw with the inner circumferential surface F of the body hole, so the damage as shown by the zigzag line 6 in FIG. The load acts on the jaw as mere compressive stress. However, it goes without saying that it is desirable that such a bearing surface be formed over the entire range of movement of the plunger 4. In this embodiment, a slot 1J drilled in the body 1
The dimensional relationship between Ill, the wedge groove 5, and the wedge portion 12 of the master jaw 2 is D> in the 8th In.
The relationship B>C and C<A<D is established. Further, the maximum length of the wedge portion 12 in the master section 2 is approximately equal to the section length Q. The reason for this is to obtain a mechanically sufficient cross-sectional engagement, make the wedge portion 12 lighter, and minimize the reduction in gripping force due to centrifugal force. Furthermore, the slot Will in the body 1 has a shape that leaves an appropriate amount of thick wall portion W toward the outside in the radial direction to prevent a decrease in body rigidity, and to prevent the plunger 1 or the master jaw 2 from rotating. Even if the wedge portion 12 should be damaged, the broken pieces will not be scattered outside. (Other Embodiments) As other embodiments, the wedge groove shape of the plant is not only a simple T-shape as shown in the 8th [4th example] but also a notch shape as shown in FIG. 11. However, in order to prevent damage to the extreme part by dispersing the concentrated stress due to the slope acting on the first surface T, or to prevent damage to the extreme part, the jaw part is formed of a straight line or a curved line whose thickness gradually decreases toward the wedge groove 5, as shown in the shape shown in the twelfth figure. By forming it into a reasonable shape corresponding to the bending moment M which is a load, it is possible to further improve strength and safety. Furthermore, the wedge portion of the body is other than the one in which the wedge member is interrupted in the middle as shown in the seventh illustrated example. As shown in Figs. 13 and 14, the radial direction of the [lu
+t may be increased or the processing may be made easier. Furthermore, it is needless to say that the arrangement is not limited to the rear inward position as shown in the example shown in FIG. [Effect of the invention 1 The present invention is as follows.
Due to the characteristics of its external shape, it can be made lighter and stronger than ever before.In the case of a plunger, the parts that are mechanically weak can be particularly reinforced with the rigidity of the body, so it can be made stiffer and stronger than ever before. In the body, the rigidity is not affected in any way by providing a slot groove that leaves an at-thick part toward the outside in the radial direction. Furthermore, by nurturing these into mechanically rational combinations,
The new chuck structure has a balance of strength that is 7J compared to the conventional one, and has significantly improved rigidity, a powerful super gripping force, and a flying lid-like grip with 5 gripping accuracy. This means that improvements can be made. Furthermore, the IJ construction, which allows the reinforcing member to be accommodated in the slot groove of the body, not only makes it possible to reduce the thickness of the chuck body, but also increases the amount of axial movement of the plunger. This has a significant effect of increasing the amount of movement. And t! Improving the grip strength is particularly effective in increasing the cutting speed to speed 1 and preventing a decrease in accuracy that accompanies this speed increase. What's more, the lighter engine has a remarkable effect in reducing inertia in the high rotation range. [Brief explanation of the drawings] Figures 1 to 4 show the conventional I-structure, in which Figure 1 is a vertical sectional view of the upper part of the chuck, Figure 2 is a perspective view of the master jaw, and Figure 3 is the plunger. - FIG. 4 is an enlarged view of FIG. 1 taken along the line xx'. 516 to 14 show specific examples.
The figure is a longitudinal cross-sectional view of the chuck, Figure 6 is a partial perspective view of the body, Figure 7 is a perspective view of the master jaw, Figure 8 is an enlarged view of Figure 5 taken along Y-Y' line, and Figure 9 ['21] and FIG. 10 are partial perspective views of the plunger, FIG. 1114 and FIG.
FIG. 14 is a perspective view showing another embodiment of the master machine;
FIG. 5 is a partial perspective view of a body showing a conventional sideways display. 1 ...Body 2 ...Master position 3 ...Top position 4 ...Plunger 5 ...Wedge groove 12 ... Projecting part (wedge part) 10...
... Guide groove 11 ... Slotted barrier 50 ... Wedge member 60 ... Reinforcement member Patent applicant Kitagawa Iron Works Co., Ltd. Pe°? -... ~-1 Procedural amendment IFξ is also 2L-) (Procedural amendment 11 based on the provisions of Article 17, Paragraph 2 of the Patent Act,
Display of the case Patent application No. 01-166012 2, title of the invention Chuck device 3, person making the amendment Relationship to the case Patent applicant location 0847-45-4560 (Representative) Name Kitagawa Iron Works Co., Ltd. Representative l;' ii 2-゛・4. Date of amendment order: 0 5. Number of inventions increased by amendment 6. Subject of amendment: The description and drawings are corrected. (2) Add the symbol V to each of FIGS. 8, 9, 11, and 12. (3) Full text in each figure of Fig. 7, Fig. 13, and Fig. 14 Revised specification 1, Title of the invention Chuck mounting part 2, Claims 1) Body and sliding in the axial direction of the body forward and backward A chuck device (A) in which a chuck consisting of a plunger that moves dynamically and a jaw that slides inward and outward in the radial direction of the body in conjunction with the sliding movement of the plunger is configured as follows. The slot groove 11 is formed leaving an appropriate amount of thick wall portion W on the radially outward side of the body. (a) A protruding portion 12 is provided at the rear of the plunger, and the protruding portion is formed of one wedge member 50 that engages with the wedge groove of the plunger, and a reinforcing member 60 that is orthogonal to the wedge member. (1) The reinforcing member 60 has a shape that includes a portion accommodated in the slot groove 11; and (1) the groove width A of the slot groove 11 is the weakest portion of the wedge groove 5 of the plunger. The direction from the zigzag line 6 toward the outer periphery should be narrower than the outer periphery damage end portion of the advancing zigzag line 6. 2) The wedge groove 5 of the plunger having a center line coinciding with the radial center line of the body is formed in a roof-shaped inclined surface with respect to the center line of the wedge groove 5. The chuck device described in section. 3) The chuck device according to claim 1, wherein the outer circumferential surface G of the plunger at the engagement portion T that engages with the wedge member 50 forms a bearing surface with the inner circumferential surface F of the body hole that comes into contact with the outer circumferential surface G of the plunger. . 4) The chuck device according to claim 3, wherein the bearing surface Af is formed over the entire movement range of the plunger. 5) The chuck device according to claim 3, wherein the cut width H of the end face of the jaw V outer periphery 11 of the plunger and the center of the wedge member of the plunger have a relationship H<D. 6) The chuck device according to claim 3, wherein the wedge groove of the plunger is provided with Nusumi N on both front side walls for dispersing concentrated stress. 3. Detailed Description of the Invention [Industrial Application Field 1 The present invention relates to a chuck used in a machine tool, and even in the high rotation range due to the recent trend towards high rotation speed.
This invention relates to a chuck that has the ability to provide powerful gripping force and high gripping accuracy. [Prior art l] A conventional solid chuck structure is provided with an engaging means that engages with a plunger on the inner part of the jaw corresponding to the radially inner part of the body, as shown in FIGS. 1 to 4. It is. Further, the hollow chuck TJ structure is provided with an engaging means that engages with the plunger at the rear inner part of the jaw corresponding to the axially rear part of the body and the radially inner part. It is as shown in FIGS. 1 to 2 described in the publication. However, both of the engaging means of the former and the latter have a drawback in that the acting force cannot be transmitted in a reasonable manner when transmitting the acting force to the engaging part of the jaw via the engaging part of the plunger. The reason for this will be explained in detail below using the drawings. FIG. 1 is a vertical sectional view of the top part of the three-jaw chuck, and the first
As shown in FIG. 5, 33 equally divided radial guide grooves 10' are provided in the radial direction of the body 1', and a master jaw 2' shown in the second figure is slidably inserted into the guide grooves 10'. and,
The front of master unit 2' (front R and S of body 1')
A top jaw 3' is fixed to the body 1' by a bolt (not shown), and a plunger 4' is fitted into a hole at the center of the body 1' so as to be freely slidable in the axial direction. As shown in FIG. 3, wedge grooves 5' are provided on the outer periphery of the plunger 4' equally in three directions (only one direction is shown). It meshes with part 2'a. Details of the meshing state are shown in FIG. 4, which is an enlarged view taken along line xx' in FIG. 1. A chuck having a structure in which the inner part of the jaw is provided with a meshing means has the following operational drawbacks. Now, when the top jaw 3' performs an operation to grasp the outer diameter of the workpiece (not shown), a force indicated by arrow P acts radially outward on the wedge portion 2'a of the master jaw 2'. The jaw 4'b of the plunger 4', which forms the T-shaped wedge groove 4'a, has a body 1.
A bending moment M acts in the direction of the arrow from the point Q where the contact with the hole ' is separated. However, the acting force P
As the amount increases, stress is concentrated on that part and damage as shown in the zigzag line 6 progresses. On the other hand, when the top jaw 3' is operated to grasp the inner diameter of the workpiece (not shown), a force in the direction opposite to the arrow P is applied to the wedge portion 2'a of the master jaw 2' radially inward. and due to the action of this force, the plunger 4
The jaw 4'b forming the T-shaped wedge groove 4a has a
A bending moment M acts in a direction opposite to the direction of the arrow. That is, both a force in the direction of arrow P and a force in the opposite direction to arrow P act on the jaw portion 4'b. In other words, the jaw portion 4'b has the disadvantage of having to carry both loads lR1. The action of force on the 1 part 4'b is the same in the chuck of the conventional structure in which the engagement means is provided at the rear inner part of the jaw.In both engagement means, the engagement on the plunger side The engagement part on the plunger side bears the unilateral swing load of the two wedge members, whereas the engagement part on the plunger side bears the unilateral swing load on the jaw part. The mechanical strength is weaker than that of the mating part, and eliminating this difference in strength between the two engaging parts was an extremely roundabout technique considering the structure of conventional chucks. Moreover, this dynamic strength difference tends to further expand as the gripping force increases, which is a particularly problematic problem in the high rotation range.

[Problem a that the invention seeks to solve]

The present invention solves many of the drawbacks of the conventional chucks, and in particular improves the strength of the engagement part on the plunger side from a mechanical standpoint, and also combines the plunger body with a rational shape. None 5 The main focus is to obtain a powerful plunger with extremely low distortion and a body that is not affected by rigidity. (Means for Solving the Problem 1) However, the present invention has a special body structure and a special plunger structure as described below. The feature is that the groove width A of the slot 1-groove 11, which is formed by leaving an appropriate amount of thick wall portion W on the radially outward side of the body, is the same as that of the wedge 1l15 of the plunger. This is a chuck device whose gist is that the direction from the most fragile part to the outer periphery is narrower than the outer periphery failure end part of the advancing zigzag line 6. Then, the force on the protrusion 12 of the jaw 2 that is generated when the workpiece is gripped by the action force of the plunger 4 is divided into a surface pressure load component and a bending load component, and the surface pressure load is divided into Wedge member 5
0 carries the burden and none. The bending load is borne mostly by the reinforcing member 60. Only by using such a component force loading method can the jaw V forming the T-shaped wedge groove of the plunger 4 need to load only the oscillating load iil, and in this case, the groove width A of the slot Wll In order to improve the strength of the jaw portion V, it is necessary that the diameter of the jaw portion V be narrower than the outer circumferential damage end portion. Furthermore, in order to completely bear the increased bending load that occurs with strong gripping, a chuck is used in which the reinforcing member 60 has a portion accommodated in the slot groove 11. (Example 1) An example of the chuck according to the present invention will be explained in detail using FIGS. 5 to 9. FIG. 5 is a longitudinal cross-sectional view of a three-jaw chuck, and FIG. FIG. 7 is a perspective view of the master charge 2, FIG. 8 is an enlarged view taken along the line Y-Y' in FIG. 5, and FIG. 9 is a perspective view of the plunger 4. As shown in , the body 1 is provided with guide grooves 10 equally divided in three directions (only one direction is shown) in which the master jacket 2 is inserted in the direction of the arrow Z 7, that is, from the inside to the outside in the radial direction. In addition, the groove bottom of the guide groove 10 is provided with a slot groove 11 having a width A and a constant length K that is narrower than the groove width and leaves an appropriate amount of wall thickness W toward the outside in the radial direction. Ori,
A part of the reinforcing member 60 forming the protrusion 12 of the master jaw 2 shown in FIG. 7 is accommodated in the slot groove 11. At this time, although the groove width A of the slot groove in this embodiment is not shown, it is characterized in that it is made narrower than the outer circumferential breakage end portion of the plunger 4. Preferably, as shown in FIG. When supporting the outer circumferential surface G of the plunger 4 with the inner circumferential surface F of the hole at the center of the body to form a bearing surface to be described later, it is desirable that the width B of the outer circumferential groove of the wedge portion of No. 4 is approximately equal. The gap between the outer circumferential surface G and the inner circumferential surface F is set to a minimum value within a range in which the plunger 4 can slide in the axial direction to maintain grasping accuracy. Furthermore, in order to make the grasping force stronger than ever, plunger 4 is used as shown in Figure 8.
The structure is such that the outer peripheral surface G of the body 1 is supported by the inner peripheral surface F of the hole in the body 1 to form a bearing surface, and the damage caused by the zigzag line 6 shown in FIG. It also completely prevents. The wedge portion of the plunger 4 in this embodiment is as follows. It is cylindrical as shown in FIG. 9, and is formed into an arc up to the edge of the wedge groove 5, so as to be in sufficient contact with the inner circumferential surface F of the hole at the center of the body. Even when cutting a part of this arc due to the meshing relationship with the master jaw 2, which is desirable from the formation of the bearing surface described above, the cutting width H is as shown in FIG.
If the width of the wedge is made smaller than that of the master wheel 2, similar effects of the bearing surface can be obtained. In the above embodiment, as shown in FIG. 7, the mask-piece 2 is provided with a wedge portion 12, which is a protruding portion, toward the rear and inward side thereof. The wedge portion 12 includes a wedge member 50 that generates a wedge action when engaging with the wedge groove 5 of the plunger 4 shown in FIG. 9, and a reinforcing member 60 that is perpendicular to the wedge member and mechanically reinforces it. The wedge member 50 mainly bears the surface pressure load during meshing, and the reinforcing member 60 mainly bears the bending load during meshing. However, the required shape of the reinforcing member 60 is such that its section modulus Z is large so as to be effective against bending loads during meshing. When S is L, Z=CL”/6 (C,
(L is shown in FIG. 7) is to be increased. In this embodiment, the slot groove 11 is formed on the outer side in the radial direction of the body 1, and the reinforcing member 60 has a shape that includes a portion accommodated in the slot groove 11, so that the above-mentioned dimensions can be made extremely large. This is something that has been devised. At this time, the shape of the outer end surface of the reinforcing member 60 is not made into a straight line as shown in FIG. 7, but is made similar to the bending moment curve shown in Figure IIA, which is mechanically reasonable, except that processing is difficult. Good. Considering this with respect to the strength of the master joint 2, the mechanical strength of the wedge member 50 is sufficient as long as the shape has sufficient dimensions to withstand the above-mentioned surface pressure load, and the mechanical strength of the reinforcing member 60 is the above-mentioned mechanical strength. The shape may have sufficient dimensions to withstand the bending load. The reinforcing member 60 constituting the wedge portion 12 of this embodiment is
Since it has a shape that includes a portion accommodated in the slot groove 11 of the body 1, a considerably large section modulus Z can be obtained, and it can sufficiently withstand excessive bending loads. It is. In this embodiment, the slot groove 1 bored in the body 1
In FIG. 8, the dimensional relationships among the wedge portion 12, the wedge groove 5, and the wedge portion 12 of the master groove 2 are such that D>B>C and C<A<D. Further, the maximum length of the wedge portion 12 in the master section 2 is approximately half of the section length Q. The reason for this is to obtain a section modulus with mechanically sufficient strength, to make the wedge portion 12 lighter, and to minimize the reduction in gripping force due to centrifugal force. Furthermore, the slot groove 11 in the body 1 is shaped to leave an appropriate amount of thick wall portion W toward the outside in the radial direction to prevent a decrease in body rigidity. Even if 12 were to break, the broken pieces would not be scattered outside. (Function) This embodiment is constructed as described above, and when the cylinder (not shown) is operated and the outer diameter of the workpiece is grasped by the top jaw 3, the wedge portion 12 of the master jaw 2 is moved radially inward. The force of is applied. Therefore, the acting force acts in a direction that presses and destroys the jaws T of the jaws V of the plunger 4. Considering this from the viewpoint of strength, the shape of the plunger 4 has a size sufficient to stop the above-mentioned acting force from being received by the jaw portion T of the T portion V. However, (1) If the load is further increased, the Wj jaw portion V itself will move as shown by the arrow P as shown in FIG.
Bending moment in the direction M! i: In such a case, the outer circumference of the zigzag line 6 that extends in a direction from the weakest part of the jaw V toward the outer circumference is the outer circumferential breakage end of the outer circumferential surface G of the jaw V. Throno narrower than the part (-groove 1
By supporting the inner circumferential surface (7) of the body hole formed with a width A1 of 18, it is completely possible to prevent damage such as the zigzag V & 6 shown in FIG. 4 from progressing. [Other Embodiment 1] As another embodiment, the wedge groove shape of the plunger is not limited to the exposed T-shape as shown in the example shown in the eighth figure.
Forming a numeric N as shown in Figure 1 to disperse the concentrated stress due to the force acting on the II facing and preventing damage to the extreme parts, or a wedge, lI5 as in the shape shown in Figure 12.
In the opposite direction, the jaw part V is formed with a straight line or a curved line whose thickness gradually decreases to obtain a rational shape that corresponds to the bending moment M that is the load, thereby further increasing the strength and safety of the layer. Be able to do this. In addition to the wedge portion shown in FIG. 7, the wedge member is interrupted in the middle. No. 131!14 As shown in Figure 14, even if the three jaws are completely opened to the front, the amount of movement in the radial direction of the jaw can be increased and the machining can be facilitated. good. Further, it is needless to say that the arrangement is not limited to the rear inward position as shown in the example shown in the seventh figure, but may be provided at the rear center where the effects of the present invention can be obtained. [Effects of the Invention] Since the present invention is configured such that the groove width A of the slot groove 11 is narrower than the breakage end portion of the zigzag line 6 on the outer periphery of the plunger 4, the plunger has the following effects. The mechanically weak points can be particularly supported by the rigidity of the body and can be made to act as compressive stress, making it stronger than ever before. By creating a slot groove that leaves a thick portion, the rigidity will not be affected in any way by the design. Furthermore, the chuck structure obtained by configuring these into a mechanically rational combination has a balanced mechanical strength compared to conventional ones, has significantly improved rigidity, and is extremely strong. Grasping power can be obtained, and grasping accuracy can be dramatically improved. Furthermore, the structure in which the reinforcing member can be accommodated in the insertion slot of the body allows the body thickness of the chuck to be made extremely thin, as well as increasing the amount of movement of the plunger in the radial direction. The larger the amount, the more effective it is. Improving the gripping force is particularly effective in increasing the cutting speed and preventing the accuracy from decreasing due to this speed increase. In addition, the lightweight protruding portion of the engine has a remarkable effect in reducing inertia in the high rotation range.

[Brief explanation of the drawing]

Figures 114 to 4 show the conventional structure; Figure 1 is a vertical sectional view of the upper part of the chuck, Figure 2 is a perspective view of the master turn, Figure 3 is a partial perspective view of the plunger, and Figure 4 is a partial perspective view of the plunger. is the first
5 to 14 show specific embodiments. FIG. 5 is a #X sectional view of the chuck, FIG. 6 is a partial perspective view of the body, and FIG. Figure 7 is a perspective view of Master Jiyou. FIG. 8 is an enlarged view cut along the Y-Y' line in FIG. 5, FIGS. 9 and 10 are partial perspective views of the plunger, and FIGS. 171 and 1
Figure 2 shows another example of the wedge groove shape of the plunger.
3 and 14 are perspective views showing other embodiments of the master machine, and FIG. 15 is a partial perspective view of a body showing a conventional structure. Master position 3...Top position 4...Plunger 5 (4'a)...Wedge groove 12.
...Protruding part (wedge part) 10 ...Guide groove 11 ...Slot groove 50 ...Wedge member reinforcing member ■ Jaw part

Claims (1)

[Claims] 1) A body, a plunger that is located at the center of the body and slides forward and backward in the axial direction, and that moves inward and outward in the radial direction of the body in conjunction with the sliding movement of the plunger. A chuck device for holding a workpiece, in which a chuck consisting of a jaw that slides in a direction is configured as follows (a) the body is provided with a guide groove for the jaw integrally formed; (B) At the groove bottom of the guide groove, a slot groove 11 having a width narrower than the groove bottom width is formed leaving an appropriate amount of thick wall portion W on the radially outward side of the body; ) A protruding portion is provided at the rear of the plunger, and the protruding portion is formed of one wedge member 50 that engages with the wedge groove of the plunger, and a reinforcing member 60 that reinforces the wedge member; The reinforcing member 60 is perpendicular to the wedge member 50, has a width C of the reinforcing member 60 that is narrower than the width D of the wedge member 50, and is formed in a shape extending in the radial direction of the body; (e) The reinforcing member 60 has a shape that includes a portion to be accommodated in the slot groove 11. (f) The reinforcement member 60 has a shape that includes a portion that is accommodated in the slot groove 11. It must be shaped so that it can be installed facing towards the user. 2) The workpiece according to claim 1, wherein the wedge groove of the plunger having a center line in the radial direction of the body is formed on a roof-shaped slope with respect to the center line of the wedge groove. Holding chuck device. 3) The workpiece according to claim 1, wherein the outer circumferential surface G of the plunger at the engagement portion T that engages with the wedge member 50 forms a bearing surface with the inner circumferential surface F of the body hole in contact therewith. Chuck device for holding objects. 4) The chuck device for holding a workpiece according to claim 3, wherein the bearing surface is formed over the entire range of movement of the plunger. 5) The chuck device for holding a workpiece according to claim 3, wherein the cut width H of the outer peripheral front end face of the wedge portion of the plunger and the wedge member width D of the plunger have a relationship of H<D. . 6) The chuck device for holding a workpiece according to claim 3, wherein the wedge groove of the plunger is provided with notches N on both front side walls for dispersing concentrated stress. 7) Length L of the reinforcing member 60 at the rear part
A chuck device for holding a workpiece according to any one of claims 1 to 6, wherein the maximum length of the chuck is half of the total length l. 8) The chuck device for holding a workpiece according to any one of claims 1 to 7, wherein the length L of the reinforcing portion 60 is formed to become gradually smaller toward the tip.