JPH0364247B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is applicable to automatic feeding of a constant velocity joint outer ring (hereinafter referred to as a workpiece) used in automobiles, etc. to a processing machine such as a grinder. This relates to the chuck used to hold the workpiece.

[Conventional technology]

As shown in FIG. 1, the work 1 has a hemispherical socket 3 formed at the end of a shaft 2, and a plurality of track grooves 4 provided on the inner periphery of the socket 3. When the track groove 4 of such a workpiece 1 is finished by a grinder, the workpiece 1 is cut into a backing plate 5 provided in the chuck part of the grinder.
The socket 3 is fitted into the positioning recess 6 to be positioned, and the socket 3 is clamped by a collect chuck 7 located outside the socket 3.

The above-mentioned grinding machine rotates the collect chuck 7 at a set angle around a swing axis perpendicular to the axis of the collect chuck 7, and presses the grindstone against the track groove 4 of the workpiece 1 which rotates together with the chuck 7. When a gap is created between the back face surface 8 of the workpiece 1 held by the collect chuck 7 and the bottom surface of the positioning recess 6 for finishing machining, the distance from the bottom surface of the recess 6 to the arcuate center of the track groove 4 (referred to as center height) does not match the set dimension, making it impossible to perform highly accurate processing.

[Problem to be solved by the invention]

Therefore, to increase machining accuracy, workpiece 1
It is necessary that the entire back face surface 8 is set accurately between the bottom surfaces of the recess 6 without any gaps.

By the way, when automatically feeding the workpiece 1 to a grinding machine, a chuck that can clamp the workpiece 1 from the inside is required. The chuck is required to have a function that allows the workpiece 1 to be accurately set in the chuck portion on the grinding machine side.
In addition, it is necessary to move the chuck between the supply part of the workpiece 1 and the grinding machine and stop it accurately so that the center of the chuck coincides with the center of the chuck on the grinding machine. Since control is extremely difficult and impossible in practice, it is necessary to ensure that the workpiece 1 is set in the chuck on the grinding machine side even if misalignment occurs between the chuck stop position and the center of the chuck on the grinding machine. The ability to obtain information is also required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a chuck for holding a workpiece that can reliably feed the workpiece to a processing machine such as a grinder at an accurate position.

[Means to solve the problem]

In order to solve the above problems, the technical matters adopted in this invention are as follows. That is, the chuck body 20 is constructed by a combination of a support tube 10 and a chuck body 20, the inner surface 13 of the chuck support tube 10 is tapered, and the chuck body 20 is inserted into the inside of the chuck support tube 10 so as to be slidable within a certain range in the vertical direction. The above tapered inner surface 1 is on the outer peripheral surface of
Form a taper cone 25 that matches 3.

A spring 28 is interposed between the chuck support tube 10 and the chuck body 20 to bias the chuck body 20 in a direction in which the taper cone 25 engages with the tapered inner surface 13.

A cylinder 31 formed in the chuck body 20
The piston 29 is slidably inserted into the chuck body 20, and the tip of the piston rod 34 of the piston 29 is inserted into the inside of the claw support cylinder 35 forming a part of the chuck body 20.

A cone 36 for pushing and expanding the pawl is provided at a portion of the piston rod 34 inserted into the pawl support cylinder 35.

A plurality of through holes 3 in the radial direction are provided in the claw support cylinder 35.
7 are formed at equal intervals, and engaging claws 38 protruding from the outer diameter side end portions of the through holes 37 are slidably inserted into each through hole 37.

A spring 40 is provided on the chuck body 20 to bias the engaging claw 38 toward the inside of the claw support cylinder 35.

A step 23a is provided on the outer periphery of the pawl support tube 35 in a direction to enlarge the outer diameter, and the step 23a is provided at a position where the pawl support tube 35 hits the end surface of the workpiece 1 before hitting the bottom surface of the socket 3.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 2, the chuck according to the present invention has a chuck support tube 10 and a chuck body 20 supported by the chuck support tube 10.

The chuck support tube 10 has an upper guide tube 11 and a lower guide tube 12 at the upper and lower ends, and the inner surface 13 between the two guide tubes 11 and 12 is tapered.
3 and are combined so that they can be slid relative to each other in the vertical direction within a certain range.

The chuck body 20 includes a cylinder member 21,
The cylinder member 21 is composed of a head cover 22, a rod cover 23, and a claw support cylinder 35. The head cover 22 is placed on the upper part of the cylinder member 21, and the rod cover 23 is placed on the lower part of the cylinder member 21. These three members are connected together by bolts 15. In addition, the claw support cylinder 35 is connected to the rod cover 2.
3, and both are integrally connected by bolts 16.

A taper cone 25 is formed on the outer peripheral surface of the cylinder member 21 . This portion of the tapered cone 25 is fitted onto the inner surface 13 of the chuck support tube 10 so that it can move up and down within a certain range. Further, a cylinder 31 is formed on the inner peripheral surface of this cylinder member 21, and a piston 29 is inserted into the cylinder 31.

The head cover 22 has an annular wall 24 formed on the lower surface of its outer periphery, and the annular wall 24 is fitted onto the upper guide tube 11 of the chuck support tube 10 so as to be vertically movable. Further, an annular fitting protrusion 17 that tightly fits into the upper end of the cylinder 31 is provided at the center of the lower surface of the head cover 22 . A piston 29 is inserted into a recess 30 formed inside the fitting protrusion 17.
fixing nut 18 to the piston rod 34 of
come and go freely. The recess 30 communicates with the upper end of the cylinder 31, and together with the cylinder 31 forms an upper pressure chamber above the piston 29.

The upper outer peripheral surface of the rod cover 23 is fitted inside the lower guide tube 12 of the chuck support tube 10. Further, a rod insertion hole 19 is provided in the center portion of the rod cover 23, and the rod insertion hole 19 is provided at the center of the rod cover 23.
The piston rod 34 is slidably inserted into the lower half of the piston 9 in a fluid-tight manner. Further, the upper half of the insertion hole 19 is formed into a fitting protrusion 17a, the inner diameter of which is larger than the piston rod 34. The fitting protrusion 17a is tightly fitted to the lower end of the cylinder 31, and the gap between it and the piston rod 34 communicates with the lower end of the cylinder 31, forming a lower pressure chamber together with the cylinder 31 at the lower part of the piston 29.

Fluid passages 32 and 33 communicate with the upper pressure chamber and the lower pressure chamber, respectively, and one fluid passage 32 communicates with the upper pressure chamber and the lower pressure chamber, respectively.
When fluid such as oil is supplied to the other fluid passage 33, the piston 29 descends, and when fluid is supplied to the other fluid passage 33, the piston 29 ascends.

Further, a plurality of pusher insertion holes 26 are formed in an annular arrangement on the upper surface of the rod cover 23 facing the lower surface of the chuck support tube 10, and each of the pusher insertion holes 26 has a cylindrical pusher 27 with a rounded tip. A spring 28 that presses the pusher 27 against the lower surface of the chuck support tube 10 is incorporated. The spring 28 presses the chuck support cylinder 10 and the chuck main body 20 in the direction of separating them in the axial direction, thereby causing the tapered inner surface 13 and the tapered cone 20 to
A biasing force is exerted in the direction in which the two engage with each other.

Piston rod 3 supporting the piston 29
The lower end of the piston rod 4 passes through the rod insertion hole 34a of the rod cover 23 and is inserted into the through hole 41 of the claw support cylinder 35 fixed to the lower surface of the rod cover 23, and the end of the piston rod 34 inserted into the through hole 41 has a claw. A cone 36 for pushing and spreading is provided.

The claw support tube 35 is provided concentrically with the rod cover 23, and a stepped portion 23a is formed on the outer periphery of the lower surface of the rod cover 23 in a direction in which the diameter thereof increases. This stepped portion 23a is formed at a height such that the lower end of the claw support tube 35 comes into contact with the end surface of the workpiece 1 before it comes into contact with the bottom surface of the socket 3 of the workpiece 1.

A plurality of radial through holes 37 are formed at equal intervals on the outer periphery of the claw support cylinder 35 (see FIG. 4),
The engaging claws 38 are slidably inserted into the respective through holes 37, and the ends of the springs 40 are engaged with the engaging holes 39 formed at the inner ends of the respective engaging claws 38. The inner end is urged against the outer periphery of the cone 36.

The chuck of the embodiment has the above structure, and in order to automatically feed the workpiece 1 to the grinding machine using this chuck, the loader 50 is movably provided between the work supply section and the grinding machine, and the loader 50 is moved. A chuck arm 51 supported at the lower end so as to be movable up and down.
Attach the chuck support tube 10 of the chuck to the chuck.

Now, drive the loader 50 to position the chuck above the workpiece 1 in the workpiece supply section, lower the chuck together with the chuck arm 51, and insert the claw support tube 35 inside the workpiece 1. The stepped portion 23a comes into contact with the upper end surface of the workpiece 1 (see FIG. 2). When the chuck arm 51 further descends, the chuck main body 20 is restricted from descending due to contact with the workpiece 1, while the chuck support tube 10 descends against the elasticity of the spring 28, causing the chuck support tube 10 to move downward. A gap is formed between the tapered inner surface 13 and the tapered cone 25 of the chuck body 20.

As described above, when the chuck body 20 moves downward with respect to the chuck support tube 10, the spring 28 contracts, and the elasticity of the spring 28 pushes down the workpiece 1 via the stepped portion 23a. Therefore, if the workpiece 1 has an inclination, the inclination is corrected and the entire back face surface 8 of the workpiece 1 is evenly pressed against the workpiece support surface 8a.

In this state, oil is supplied to the fluid passage 33, and the engaging claw 38 moves outward by the claw pushing and expanding cone 36 of the piston rod 34, and its tip comes into pressure contact with the inner surface of the workpiece 1, pushing the workpiece 1 inward. to hold from.

Next, when the chuck arm 51 is raised, the chuck support tube 10 is lifted together with the chuck arm 51.
rises, and the tapered inner surface 13 engages with the taper cone 25. This engagement holds the workpiece 1 on the axis of the chuck body 20, and as the chuck arm 51 further rises, the workpiece 1 is lifted. The workpiece 1 can be taken out from the workpiece supply section.

After raising the workpiece 1 to a predetermined position, the loader 50 is moved to transport the workpiece 1 in the direction of the grinder, and after positioning the workpiece 1 above the grinder, the chuck arm 51 is lowered. As shown in FIG. 3, the shaft 2 of the work 1 fits into the hole 9 formed in the backing plate 5 of the grinding machine, and the back face surface 8 of the work 1 comes into contact with the bottom surface of the positioning recess 6. When the chuck arm 51 further descends, only the chuck support cylinder 10 descends against the elasticity of the spring 28 in the same manner as described above, a gap is formed between the tapered inner surface 1 and the tapered cone 25, and the chuck main body 20 Within the range where the outer periphery of the taper cone 25 contacts the tapered inner surface 13, the tapered cone 25 enters a floating state in which it can move in any direction.

Therefore, even if the work 1 is not fully supplied to the chuck of the grinding machine and there is a gap between the back face surface 8 of the work 1 and the bottom surface of the positioning recess 6, the work 1 is pressed downward by a spring 28 provided between the chuck body 20 and the chuck support cylinder 10, and its back face 8 is pressed against the bottom of the recess 6, correcting its posture.

The workpiece 1 is then clamped by the collector chuck 7 of the grinding machine while being clamped by the chuck body 20. If the center of the chuck body 20 and the center of the collector chuck 7 do not match, the workpiece 1 is clamped by the collector chuck 7. When the chuck body 20 is clamped, the chuck body 20 moves to a position that coincides with the center line of the back face surface 8 due to the existence of a gap between the chuck body 20 and the chuck support tube 10. As a result, problems such as uneven wear on the chucked surface of the workpiece 1 and twisting of the engagement claw 38 do not occur, and the workpiece 1 can be reliably clamped by the collect chuck 7.

As shown in FIG. 3, if an engagement hole 52 is formed on the lower surface of the loader 50 and a protrusion 53 that can fit into the engagement hole 52 is provided on the grinder, the workpiece can be easily attached to the grinder. 1, the loader 50 can be positioned by the engagement between the protrusion 53 and the engagement hole 52, so that the workpiece can be supplied to the center of the chuck of the grinding machine.

In addition, as shown in FIG.
An L-shaped engaging piece 54 is provided on the grinding machine, and a positioning hole 55 is formed on the side of the grinding machine into which the end of the engaging piece 54 can fit, and when the chuck main body 20 is lowered toward the chuck of the grinding machine. By fitting the end of the engaging piece 54 into the positioning hole 55, the workpiece 1 can be fed to the chuck of the grinding machine in the same orientation as the workpiece 1.

〔Effect of the invention〕

As described above, according to the present invention, the stepped portion 23a provided on the claw support tube 35 at the lower end of the chuck main body 20
The chuck support tube 10 is lowered with the chuck supporting tube 10 in contact with the upper surface of the workpiece 1, or
By lowering the chuck support tube 10 with the back face surface 8 of the workpiece 1 supported by the grinder in contact with the bottom surface of the positioning recess 6 formed in the backing plate 5 of the grinding machine, the taper inner surface 13 and the taper cone 25 are lowered. A gap is formed between the spring 28 and the spring 28 at the same time.
The chuck main body 20 can be pushed downward with the elastic force of 8.

Therefore, when the workpiece 1 in the workpiece supply section is held by this chuck, the back face surface 8 of the workpiece 1 can be pressed against the workpiece support surface 8a of the workpiece supply section, thereby causing the workpiece to be tilted. However, the slope can be corrected. Therefore, the workpiece 1 can be held without tilting.

In addition, when the workpiece 1 clamped by this chuck is fed to the chuck part of the grinding machine, the entire back face surface 8 of the workpiece 1 is transferred to a positioning recess 6 formed in the backing plate 5 of the chuck part.
Workpiece 1 can be pressed evenly to the bottom of the workpiece
can be positioned with high precision without tilting.

Furthermore, by forming the tapered inner surface 13 on the chuck support tube 10 and providing the taper cone 25 on the chuck body 20, the workpiece 1 held by the chuck body 20 can be held concentrically with respect to the chuck support tube 10. In addition, when the workpiece 1 is clamped by the collector chuck 7 of the grinding machine, if there is a misalignment between the axis of the workpiece 1 and the axis of the collect chuck 7 of the grinding machine, the misalignment will be corrected by forming a gap between the taper inner surface 13 and the taper cone 25. It can be absorbed by the gaps. Therefore, the workpiece 1 can be held with high precision by the collect chuck 7 of the grinding machine.

Further, according to the present invention, a series of operations such as positioning for pressing the lower surface of the workpiece 1 against the reference surface, correction of the inclination, and centering can be efficiently performed by one chuck.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a workpiece held by the collector chuck of a grinding machine, Fig. 2 is a vertical cross-sectional front view showing an embodiment of the chuck according to the present invention, and Fig. 3 is a grinding workpiece held by the same chuck. FIG. 4 is a cross-sectional front view showing a state in which it is set in the chuck of the board, FIG. 4 is a cross-sectional plan view of FIG. 3, and FIG. 5 is a side view of the same. 1... Work, 2... Shaft, 3... Socket, 4... Track groove, 5... Backing plate, 6... Recess, 7... Collection chuck, 8...
...back face surface, 8a...work support surface, 1
0...Chuck support tube, 11...Upper guide tube, 1
2... Lower guide tube, 13... Inner surface, 15... Bolt, 16... Bolt, 17... Fitting protrusion, 17a
... Fitting protrusion, 18 ... Nut, 19 ... Rod insertion hole, 20 ... Chuck body, 21 ... Cylinder member, 22 ... Head cover, 23 ... Rod cover, 23a ... Step part, 24 ... annular wall, 25
... Taper cone, 26 ... Pusher insertion hole, 2
7... Pushya, 28... Spring, 29...
Piston, 30... Recess, 31... Cylinder, 3
2...Fluid passage, 33...Fluid passage, 34...Piston rod, 34a...Rod insertion hole, 35...
...Claw support tube, 36...Claw pushing cone, 37
...Through hole, 38...Engagement claw, 39...Engagement hole,
40...Spring, 41...Through hole.

Claims (1)

[Claims] 1 Consists of a combination of a chuck support tube 10 and a chuck body 20, the inner surface 13 of the chuck support tube 10 is tapered, and the chuck support tube 10
A taper cone 25 that matches the tapered inner surface 13 is formed on the outer circumferential surface of the chuck body 20 that is slidably inserted within a certain range in the vertical direction. A spring 28 that biases the chuck support tube 10 and the chuck body 20
The piston 29 is slidably inserted into the cylinder 31 formed in the chuck body 20, and the tip of the piston rod 34 of the piston 29 is inserted into the inner side of the claw support cylinder 35 forming a part of the chuck body 20. A cone 36 for pushing and expanding the claw is provided at the insertion portion, and a plurality of through holes 37 are formed in the claw support tube 35 at equal intervals in the radial direction, and a hole is inserted into each through hole 37 from the outer diameter side end thereof. The chuck body 20 is provided with a spring 40 into which the protruding engagement claw 38 is slidably inserted and which biases the engagement claw 38 toward the inside of the claw support tube 35. A step 23a is provided in the direction of increasing the outer diameter, and the step 23a is connected to the claw support tube 3.
A chuck is provided at a position where the chuck 5 hits the end face of the work 1 before it hits the bottom face of the socket 3 of the work 1.