JPH02292102A - Crank shaft holding chuck - Google Patents

Abstract

PURPOSE:To allow the setting of many types of eccentricity by providing a reference stopper on a fixing member which is located on the opposite side in a slide direction of a screw shaft of a slider. CONSTITUTION:When the drive shaft 38 of a nut liner 37 is engaged with a screw shaft 35 to make positive rotation of the liner 37 for sliding a slider 4 to a D1 direction, the end face 40a of the stopper 40 of the slider 4 is pressed against the end face 41a of the reference stopper 41 of a fixing member 7 as shown by broken lines, so that the rotation resistance of the liner 37 is detected by a control device 39 to stop the rotation of the liner 37 for stopping the slider 4. The position of eccentricity (S) to the rotation center line l2 of a main axis 2 is acknowledged as an initial position by the control device 39. The slider 4 is then slided to a D2 direction by the reverse rotation of the liner 37 so that the eccentricity (d) of the slider 4 to the rotation center line l2 of the main shaft 2 is moved DELTAX more than the eccentricity (d1), and then returned the extra distance DELTAX to a D1 direction, where the slider 4 is clamped.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chuck for holding a crankshaft when grinding a crankshaft part, and in particular to a chuck for holding a crankshaft with respect to the center of rotation of the main shaft in response to changes in the amount of eccentricity of the crankpin. This invention relates to a crankshaft holding shaft that can automatically adjust the eccentricity of the center of the journal support metal.

Conventional technology> The method of holding the crankshaft on the main shaft during grinding of the crank pin is to attach an eccentric chuck to the tip of the main shaft, and to hold the journal part of the crankshaft in an eccentric state on this eccentric chuck. The bottle portion is positioned on the rotation center line of the main shaft. In addition, the eccentric chuck has a structure in which the eccentricity of the journal support part that supports the journal part of the crankshaft with respect to the center of rotation of the main shaft can be changed so that crankshafts with different crankshaft eccentricities can be processed. .

And there is a method to automatically change the eccentricity setting.
It is disclosed in Japanese Utility Model Publication No. 12538/1983. When changing the eccentricity of the journal support with respect to the spindle rotation center, the screw shaft that adjusts the position of the slide body fixed to the chuck body that supports the crankshaft relative to the spindle axis is rotated using a naso runner. Its positioning is structured such that the amount of eccentricity can be changed in multiple stages by switching a stepped spacer fitted between the slide body and a fixing member fixed to the main shaft.

Problems to be Solved by the Invention In the above mechanism, the amount of eccentricity of the journal support portion with respect to the center of rotation of the spindle is set by the step formed in the stepped smoother, so the amount of eccentricity depends on the thickness of the step. It can only be set depending on the position.

Since the number of steps of the stepped spacer cannot be increased very much, there is a problem that it is not possible to set various eccentricity amounts.

Furthermore, since the dimensional error in the amount of eccentricity is affected by the dimensional accuracy of the stepped portion of the stepped spacer and the fitting surface of the slide body and the fixed member, it is necessary to manufacture these members with high precision.

Means for Solving the Problems> The present invention has been made to solve the above-mentioned problems, and includes providing a reference stopper on a fixed member at a position opposite to the position of the screw shaft of the slide body in the sliding direction. , the end face of the slide body comes into contact with this reference stopper to limit the current of the nut roller sweeper, thereby setting the initial position of the slide body, and the eccentricity d of the center of the support with respect to the center of rotation of the main shaft. On the other hand, after the eccentricity d of the slider relative to the center of rotation of the main shaft is moved from the initial position by Δx than the eccentricity d1, the slider moves back by the extra distance Δx. It is equipped with a control device that controls the rotation of the Nattra lifesha.

<Operation> When grinding the crank pin part by holding the crankshaft on the main shaft by clamping the journal part at a position eccentric from the center of rotation of the main shaft, when machining crankshafts with different amounts of eccentricity of the crank bin, the chuck Adjust the position of the main body relative to the spindle axis.

It is adjusted by moving a screw shaft screwed into a slide body fixed to the chuck body by rotating the nut liner. The procedure is to first bring the end surface of the slide into contact with the tip of a reference stopper of a fixed member fixed to the main shaft, and set the initial position by limiting the current of the nut runner. Thereafter, the nutrer is rotated by the amount of eccentricity input as a command value to the control device, and the slide body slides due to the rotation of the screw shaft. The gap control device causes the slider to slide further than the input eccentricity value and then return by that extra distance. After that, the slide body is clamped to the main shaft.

Embodiments> Examples of the present invention will be described below with reference to FIGS. 1 to 3. 1 is a spindle head, 2 is a spindle supported by the spindle head 1, a face plate 3 is fixed to the front end surface of this spindle 2, and a plate-shaped slide body 4 is arranged in front of this face plate 3. There is. As shown in FIG. 3, this slide body 4 is supported by a guide member 5.5 bolted to the face plate 3 so as to be slidable in the eccentric direction of the crank pin 6a of the crankshaft 6. Further, the outer periphery of the slide body 4 and the guide member 5.5 is covered by a cylindrical fixing member 7 attached to the face plate 3.

A chuck main body 8 is fixed to the front surface of the slide body 4 with bolts 9, and a support metal 10 for supporting the journal portion 6b of the crankshaft 6 is provided at the front end of the chuck main body 8. The center axis I of the journal retaining portion 10a of this support 10 is the rotation center line l of the main shaft 2.
It is eccentric with respect to 2.

Further, as shown in FIG. 2, the support metal 10 has
A clamp arm l2 is mounted on a shaft pin 11 so as to be rotatable in a direction intersecting the journal center axis of the crankshaft 6, and is connected to the journal of the support member 10 via a presser foot 13 attached to the upper end of the clamp arm 12. Joint part 10
It is pressed from above against the journal part 6b that is engaged in the inside of the journal part 6b. The lower end of the clamp arm 12 is connected by a pin 15 to a piston rod 14a of a clamp cylinder 14 provided on the chuck body 8, and clamps the journal portion 6b on the support 10 by the forward and backward movement of the piston 14b of the clamp cylinder l4. and unclamp it.

In FIG. 1, l6 indicates the crank pin 6a of the crankshaft 6 at the center of rotation 1 of the main shaft 2. This index plate 16 constitutes a phase indexing mechanism for upward phase indexing.
is formed concentrically and integrally with a hollow indexing shaft l7 which is arranged concentrically with the central axis l1 of the journal retaining portion 10a of the support metal IO.

This indexing shaft 17 is attached to the chuck body 8 with bearing members 18 and 19.
A pin support plate 20 is integrally fixed to the end of the support metal 10 side. A reference pin 21 that engages with the crankshaft 6 is protruded from the front end surface of the pin support plate 20, and a shifter pin 21 that engages with the outer periphery of the pin support plate 20 through a pin 22 is relatively rotatable. 23 is installed. As shown in FIG. 3, the shifter 23 has a pair of arms 24, 25 extending in opposite directions.
is provided, and the tip of the one arm 24 is connected to the pivot pin 2.
6, and the tip of the other arm 25 is connected to a piston rod 27a of a shift cylinder 27 provided on the chuck body 8, so that the piston 27b of the shift cylinder 27 can be moved forward and backward. By doing so, the reference bottle 2l can be engaged with and disengaged from the crankshaft 6 by moving the bottle support plate 20 including the indexing shaft 17 in the axial direction of the indexing shaft l7.

Further, one end of a universal joint 29 made of a Schmidt coupling or the like that allows eccentricity is connected to the other end of the index shaft 17 via a spline shaft 28, and the other end of the universal joint 29 is inserted into the center of the main shaft 2. and is connected to a drive shaft 31 which is connected to an indexing drive source 30.

Furthermore, a stepped portion 16a is formed on the index temporary 16, and a positioning pin 32 that engages with this step 16a is placed inside the case 33 attached to the chuck body 8.
6 and is slidably inserted in the radial direction of the positioning pin 3.
2 is biased by a spring 34 in the direction of being pressed against the index plate 16.

In FIG. 1, reference numeral 35 denotes a screw shaft that is rotatably held by the fixed member 7 and supported in the moving direction of the slide body 4. Crankshaft 6 with different eccentricity
This is to index the position of the crank pin 6a so that it coincides with the center of rotation of the main shaft according to the amount of eccentricity during machining.

The inner protrusion of the fixing member 7 at the threaded end of the screw shaft 35 is engaged with an engagement hole 36 formed in the slide body 4, and a fixed nant 45 and a movable nut 46 are inserted into the engagement hole 36. A backlash removal mechanism consisting of a spring 47 is provided. The fixed nut 45 is fixed to the slide body 4, and the movable nut 46 is supported by a pin 48 so as to be movable only in the axial direction of the screw shaft 35 with respect to the slide body 4.

Also, the spring 47 is connected to the fixed nut 45 and the movable nut 4.
This spring 4 is inserted in a compressed state between
7, the thread of the male thread of the screw shaft 35 is fixed with the nut 45.
and the threads of the female thread of the movable nut 46 in different directions, and the play caused by the backlash of the screw shaft 35 is removed.

Further, a locking hole 35a is formed in the side of the other end of the screw shaft 35 that is exposed to the outside of the fixing member 7, and a drive shaft 38 of the nut runner 37 that rotates the screw shaft 35 in forward and reverse directions is inserted into the locking hole 35a. The head 38a of the head 38a is removably engaged. This nut runner 37 is supported by a non-rotating part of a processing device (not shown) so as to be movable forward and backward relative to the screw shaft 35.
When indexing the position of the crank pin 6a with respect to the center of rotation of the main shaft, the nut runner 37 is moved forward, its drive shaft 38 is engaged with the screw shaft 35, and the screw shaft 35 is rotated to perform the position index. do. The rotation of the nut runner 37 is controlled by a command value from a control device 39, which will be described later.

Further, a stopper 40 is fixed to the end surface of the slide body 4 opposite to the end surface where the screw hole 36 is formed.
An end surface 40a of the stopper 40 serves as a reference surface for the slide body 4. Further, a reference stopper 41 for setting an initial position is provided on the fixing member 7 at a position facing the end surface 40a,
When the end surface 40a of the stopper 40 comes into contact with the end surface 41a of the reference stopper 41, the initial position of the slide body 4 is set.

The operation of the chuck configured as above will be explained. In order to hold the crank pin 6a of the crankshaft 6 on the main shaft 2 in a state where it can be ground, first, the clamp cylinder 14 is
The piston 14b of the clamp arm 12 is moved backward.
is rotated in the eight directions of arrows in FIG. 2 and held in the unclamped state shown by the two-dot chain line. Further, the piston 27b of the shift cylinder 27 is moved backward, and the shifter 23 moves the bin support plate 20 including the indexing shaft 17 in the direction of arrow B in FIG. Let it escape so that it does not interfere with the loading.

In this state, the unprocessed crankshaft 6 is loaded into a processing position of a processing device (not shown), and the journal portion 6b of the crankshaft 6 is placed on the journal holding portion 10a of the support metal 10. After that, the piston 27b of the shift cylinder 27
is advanced to the state shown in FIG. 3, the pin support plate 20 including the indexing shaft 17 is brought into the state shown by the solid line in FIGS. 1 and 2, and the reference bin 21 is engaged with the crankshaft 6.

Then, the index drive source 30 is started to rotate in the forward direction, and the rotation is transmitted to the index shaft 17 via the universal joint 29 and the spline shaft 28.
The indexing shaft 17, the indexing plate 16 and the pin support plate 20
is rotated in the direction of arrow C in FIG. 1, and the crankshaft 6 is also rotated while being placed on the support lO. Then, the positioning pin 32 is attached to the index plate 1 as shown in FIG.
When the indexing drive source 30 is fully fitted into the stepped portion 16a of No. 6, the forward rotation of the indexing drive source 30 is stopped, and the indexing drive source 30 is rotated slightly in the reverse direction.
Press the side surface of the stepped portion 16a of No. 6 against the positioning bin 32,
This completes the phase indexing of the crank pin 6a on the rotation center line of the raw shaft 2.

Then, the clamp cylinder 14 is moved forward to rotate the clamp arm 12 to the state shown by the solid line in FIG. 2, thereby clamping the journal portion 6b of the crankshaft 6.

Now, the crank pin 6 relative to the axis of the journal portion 6b
If the eccentricity of a is d, and the eccentricity of the center line 11 of the journal engaging portion 10a of the support 10 with respect to the rotational center line l2 of the main shaft 2 is d, then the rotational center of the main shaft 2 is Journal retaining portion 10 of support metal 10 for line l2
The amount of eccentricity of the center line l at the center of a must be set to d1.

? In this case, as shown in the flowchart of Figure 5,
First, the head 38a of the drive shaft 38 of the nut runner 37 is engaged with the engagement hole 35a of the screw shaft 35, and the nut runner 37
is rotated in the forward direction to slide the slide body 4 in the direction D in FIG. Then, as shown by the broken line in FIG. 1, the end surface 40a of the stopper 40 of the slide body 4 is pressed against the end surface 41a of the reference stopper 41 of the fixed member 7, and the control device 39 detects the rotational resistance of the nut ladle key 37. , rotation of the nut runner 37 is stopped due to current limitation, and the slide body 4 is stopped. The position of the eccentricity S with respect to the rotation center line 2 of the main shaft 2 is recognized by the control device 39 as the initial position. At this time, since the end surface 41a of the reference stopper 4l is close to the center line it of the journal retaining portion 10a, the influence of thermal displacement is small and an accurate initial position can be set.

After that, the nut runner 37 is rotated in the opposite direction, and the slide body 4
Slide it in the D2 direction in Fig. 1.

The eccentricity d of the center line II of the journal retaining portion 10a of the support 10 with respect to the rotation center line 1 of the main shaft 2 is d1,
That is, if the amount of slide in the D2 direction is a, the slide is made until Sa becomes d. Then, the control device 39 further slides the slide amount a by Δx in the D2 direction, and then returns it in the D1 direction by Δx. At that position, the slide body 4 is clamped by a clamp device (not shown). By performing such control, the influence of backlash in the feed mechanism such as the nut runner 37 can be eliminated.

If the main shaft 2 is rotated in this state, the crankshaft 6 held by the main shaft 2 will be rotated around the crank bin 6a. Therefore, if a rotating grindstone is pressed against the crank bin 6a, the crank shaft 6 held by the main shaft 2 will be rotated around the crank bin 6a. 6a will be ground.

As described above, according to the present invention, when changing the eccentricity of the crank bin 6a with respect to the journal axis, the eccentricity of the support metal center of the journal part with respect to the main shaft rotation center is changed by rotating the screw shaft, so that the chuck body is aligned with the main spindle axis. against W
It is now possible to adjust and set any amount of eccentricity.

In addition, the control device first brings the nut runner that rotates the screw shaft into contact with the reference stopper at a position close to the center of the journal part, sets the initial position by limiting the current, and the eccentricity input from that initial position is achieved. By moving the slide further than the amount of movement and then returning it by that extra distance, the effect of thermal displacement of the slide body is reduced, and accuracy is improved without being affected by the play of the feed mechanism such as the nut runner. Can be figured out well.

Effects of the Invention> As described above, in the present invention, when changing the eccentricity of the journal support center with respect to the spindle rotation center,
By rotating the screw shaft, it is now possible to adjust the position of the cha-nok body with respect to the spindle axis, and set the desired amount of eccentricity.

In addition, the control device first causes the nut runner that rotates the screw shaft to come into contact with a reference stopper at a position near the center of the journal part, sets the initial position by limiting the current, and moves the nut runner from that initial position to the input eccentricity. By moving the slider by an extra distance and then returning it by that extra distance, it is possible to reduce the effect of thermal displacement of the slide body and to accurately index without being affected by the rattling of the feed mechanism such as a nut runner. I can do it.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a cross-sectional view of a crankshaft holding chuck, FIG. 2 is a cross-sectional view taken along the line (2) Line sectional view, FIG. 4 is an explanatory diagram showing the relationship between the index plate and the positioning pin, and FIG. 5 is a flow chart of the positioning system 1 of the slide body. DESCRIPTION OF SYMBOLS 1... Main shaft head, 2... Main shaft, 4... Slide body, 5... Guide member, 6... Crankshaft, 6a-crank pin, 6b... Journal portion, 7... Fixed part month, 8... Chuck body, 10... Support metal, 35.
... Screw shaft, 36 ... Engagement hole, 37 ... Nut runner, 39 ... Control device, 40 ... Stopper, 4l.
...Reference stopper, 45...Fixing nut.

Claims (1)

[Claims] (1) A slide body attached to the front end surface of the main shaft of the main shaft head so as to be slidable in the eccentric direction of the crank pin of the crankshaft;
A chuck body fixed to the slide body, a support provided on the chuck body eccentrically from the axis of the main shaft and supporting the journal portion of the crankshaft, and a fixed member fixed to the main shaft are allowed to rotate only. a screw shaft that is rotatably supported by the slide body and screwed into the slide body from a direction that corresponds to the sliding direction of the slide body, and adjusts the position of the chuck body with respect to the spindle axis; In a crankshaft holding chuck composed of a nut runner that rotates a shaft, a reference stopper is provided on the fixed member at a position opposite to the position of the threaded shaft of the slide body in the sliding direction, and the reference stopper is The initial position of the slide body is set by the end face of the slide body coming into contact and the current of the nut runner being limited, and the main shaft The nut runner is rotated so that the slide body moves an amount of eccentricity d of the slide body relative to the rotation center from the initial position by an amount of △× more than the eccentric amount d_1, and then moves the slide body back by the extra distance Δ×. A crankshaft holding chuck equipped with a control device to control the movement.