JPS59192450A - Axial material grinder - Google Patents

Abstract

PURPOSE:In a system for grinding the outercircumferential face of an axial material such as a cam shaft with a rotary grindstone while rotating, to improve the work efficiency by positioning the center of axial material through a resting means for supporting more than two circular cross-section separated in axial direction. CONSTITUTION:In a system for grinding a cam shaft (S) fixed to a rolling member rotatably with a master cam by means of a grindstone 20 rollable with the rolling member through the master cam, the cam shaft (S) is supported between a tailstock barrel 24 and a work spindle 22 supported at the free end of the rolling member. A resting means 36 including two three-point rests 28, 30 and two-point rests 32, 34 and an axial direction positioner 38 are provided on a guide rail 26 for guiding a tailstock for supporting the tailstock barrel 24 where the journal sections J2-J5 of the cam shaft (S) are supported in the resting means 36. Furthermore a floating driver 40 is provided to the work spindle 22.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a grinding device that can efficiently grind a camshaft equiaxial object while maintaining high processing accuracy.

Cam profile grinding of a camshaft is generally carried out by having the camshaft supported at two centers facing each other, and rotating the camshaft by engaging a drive device with a bin installed upright on one end of the camshaft. . However, in this case, if the feed rate, that is, the relative movement speed in the axial direction between the grinding wheel and the camshaft, is increased above a certain value at a constant depth of cut, a phenomenon occurs in which the camshaft rotates by a small angle around the pin as a fulcrum. This causes a phase shift in the resulting cam profile, so machining efficiency is limited by the maximum feed speed at which such a phenomenon does not occur. Further, there is also the problem that poor roundness of the center hole and dust adhering to the inner circumferential surface of the center hole reduce processing accuracy.

In order to solve these problems, the camshaft is supported by a rest device and a chuck is used as a drive device, but in this case, the part to be gripped by the chuck is the journal part of the camshaft. It is necessary to grind them together in advance, and it is troublesome to adjust the centering of the chuck. If the chuck is provided with a floating function in order to avoid this trouble, the device will become complicated and the equipment cost will increase.

Although the cam profile grinding of a camshaft has been explained above as an example, the above-mentioned problems still exist in the grinding of other shaft-like objects.

Against this background, the present invention provides an apparatus for grinding a shaft-shaped workpiece by rotating the workpiece and bringing the outer peripheral surface of the workpiece part of the workpiece into contact with the outer peripheral surface of a rotary grindstone,
The purpose of this invention is to provide a grinding device that can improve work efficiency while maintaining sufficient machining accuracy and has a simple structure.

In order to achieve this objective, the grinding device according to the present invention (
a rest device that includes at least one three-point rest and supports the workpiece rotatably around the axis and movably in the axial direction in at least two circular cross-sections spaced apart in the axial direction; ) a drive device that rotates the workpiece by engaging with a portion of one end of the workpiece that is radially away from the axis of the workpiece while allowing movement of the workpiece in the axial direction and all radial directions; , (C) engages with two mutually opposite planes formed at right angles to the axis at positions separated in the axial direction of the workpiece in a state that allows rotation of the two planes about the axis. , and an axial positioning device that substantially prevents axial movement of the workpiece.

That is, in the grinding apparatus according to the present invention, the center hole is not used as a processing reference, and the axial center of the workpiece is positioned using a rest device that supports two or more circular cross-sections spaced apart in the axial direction.

It is preferable that this rest device includes two three-point rests that respectively support the vicinity of both ends of the workpiece, and one between the two two-point rests that supports two points separated in the axial direction of the workpiece. Even if one three-point rest is provided at a certain position, the purpose can be achieved to a certain extent. Furthermore, it is also possible to supplementally add a two-point rest or a three-point rest in addition to the above-mentioned rests.

In addition, the axial movement of the workpiece is performed by an axial positioning device with a simple structure that engages with two planes perpendicular to the axis and facing oppositely to each other, such as the end face or stepped surface of the workpiece. , the drive device does not need to have a function to prevent the workpiece from moving in the axial direction, but rather engages with the workpiece and rotates it while allowing the workpiece to move in the axial direction and all radial directions. What you can give is enough.

As is clear from the above explanation, the grinding device according to the present invention does not use a center to determine the axial position of the workpiece, but uses a rest device, so the grinding device applied to the workpiece Even if the load becomes large, the workpiece will not run out, and machining efficiency can be improved while maintaining sufficient machining accuracy. Moreover, since the axial movement of the workpiece is performed by an axial positioning device with a simple structure, the drive device does not need to have a function of blocking the axial movement of the workpiece. Therefore, the grinding apparatus according to the present invention can be manufactured at a lower cost than when the chuck is of a floating type.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a cam grinder for grinding a cam profile of an engine camshaft will be described below with reference to the drawings.

FIG. 1 is a diagram showing the principle of the cam grinder of this embodiment.
is a swinging member whose one end is rotatably supported, and a mask cam 12 is rotatably attached to the free end of the swinging member.
It is constantly brought into contact with the tip roller 16 by the urging force of 4. The camshaft S is attached to the swinging member 10 so as to be rotated integrally with the mask cam 12, and the mask cam 12 is rotated while maintaining contact with the grinding roller 16 to give a predetermined motion, and the cam shaft S is rotated by the grindstone 20. The profile is ground.

A portion of the swinging member 10 that supports the camshaft S is shown in FIG. A work spindle 22 is provided at the free end of the swinging member 10.
is rotatably supported, and a cardiac axis 24 is provided concentrically opposite to this. A shinshin stand (not shown) supporting the shinshin shaft 24 can be fixed at any position on a guide rail 26 having an inverted trapezoid cross section.
2 (hereinafter simply referred to as the axial direction) to a position below the work spindle 22, and above it are two three-point rests) 28.30 and two-point rests 32.34. The rest device 36 including the rest device 36 and the axial positioning device 3B are arranged in a state where the axial position can be adjusted. Also,
A floating drive device 40 is attached to the work spindle 22.
is installed.

The camshaft S whose cam profile is to be ground by the device of this embodiment is provided with individual journal parts J1 to J5, of which J2 and J5 are respectively supported by three-point rests 28 and 30, and journal parts J3 and J4 are rotatably supported by two-point rests 32 and 34, respectively. Journal part J2-J5
One cam portion C1 to C8 is provided on each side of the cam portion. Also, large diameter parts B1 and B2 are formed on both sides of the journal part J1, and stepped surfaces D1 and B2 are formed at right angles to the axis of the camshaft S at the boundary between these large diameter parts and the journal part J1. , and are formed to face each other, and the positioning member 42 of the axial positioning device 38 is fitted between these stepped surfaces DI, D2, thereby positioning the camshaft S in the axial direction. be exposed.

Center holes A1 and A2 are formed on both end surfaces of the camshaft S, respectively, and drive devices 40 are formed in each of the center holes A1 and A2.
The center 44 of the camshaft S and the center 46 of the camshaft 24 are fitted to temporarily position the camshaft S. Further, on the end face of each of the 40 drive devices for the camshaft S, a pin P is provided upright at a position radially away from the axis of the drive device.
When this pin engages with the drive device 40, the rotation of the work spindle 22 is transmitted to the cam shirt S.

Since the drive device and mask cam device for rotating the work spindle 22 are well known, illustrations and detailed explanations thereof will be omitted, and the rest device 36. Axial positioning device 38
and drive device 40 will be explained in detail.

First, regarding the rest device 36, the three-point rest 28 included therein is shown in FIGS. 3 to 5. The three-point rest 28 includes a main body 52 that is slidably fitted to the guide rail 26 in a dovetail groove 50, as shown in FIG.

A lever 56 is rotatably attached to the main body 52 by a shaft 54, and a movable rest 58 is rotatably attached to the free end of the lever 56 by a shaft 60. The movable rest 58 is urged to rotate counterclockwise by the elastic force of a compression coil spring 62 provided between it and the lever 56, and is maintained at the position shown by the solid line in FIG. 3 by a stopper (not shown). However, when it comes into contact with the journal part J2 of the camshaft S, the third
The state shown by the dashed line in the figure is reached, and based on the elastic force of the spring 62, the journal part J2 is pressed against the two fixed rests 64 and 66 fixed to the main body 52, and together with these, the journal part J2 is pushed in the circumferential direction. It is rotatably supported around an axis at three points separated by

When the camshaft S is attached or detached, the lever 56 rotates to the position shown by the dashed line in FIG. 3 and retracts the movable rest 58 to a position where it does not interfere with the camshaft S. A rank and pinion mechanism 68 as shown in FIGS. 4 and 5 is provided. That is, a pinion 70 is fixed to the above-mentioned shaft 54, and this pinion 70 is engaged with a rack 74 that also serves as a plunger of a hydraulic cylinder 72, and the pinion 70 is engaged with a rack 74 that also serves as a plunger of a hydraulic cylinder 72.
The rack 74 moves in the axial direction by supplying pressure oil to the
The lever 56 is rotated via the pinion 70. The other 3-point rest 30 is 3 above.
Since it has the same structure as the point rest 28, and the two-point rests 32 and 34 are well-known simply having two fixed rests, their explanation will be omitted.

The axial positioning device 38 includes a main body 82 that is slidably fitted to the guide rail 26 in a dovetail groove 80, as shown in FIG. Two blind holes 84 and 86 are formed in the main body 82, as shown in FIG. A piston 88 is fluid-tightly and slidably fitted into the dead-end hole 84, and a piston rod 90 extending from the dead-end hole 84 penetrates a cap 92 screwed into the opening of the dead-end hole 84 and projects to the outside. These constitute a hydraulic cylinder 94. On the other hand, a guide rod 95 is slidably fitted into the dead-end hole 86, and the positioning member 42 is fixed to the guide rod 95 and the piston rod 90. The width of the positioning member 42 at the tip is equal to that of the camshaft S.
is selected to be slightly smaller than the interval between the stepped surfaces DI and D2, and when the positioning member 42 is advanced by the hydraulic cylinder 94, this tip fits between the stepped surfaces DI and D2 and is moved back. When it comes to leaving.

As clearly shown in FIG. 6, a U-shaped notch 96 is formed in this tip of the positioning member 42, and when the tip moves forward to fit between the stepped surfaces DI and D2. Interference between the positioning member 42 and the journal portion J1 is avoided. In the forward position, the positioning member 42 has a distal end fitted into the groove 97 of the main body 82 and is prevented from moving in the axial direction of the camshaft.

The drive device 40 has a structure shown in FIGS. 8 to 10. In the figure, 98 is a main body fixed to the tip of the work spindle 22, and a drive member 100 is attached to this main body 98. This drive member 100 includes a U-shaped protrusion 102 that sandwiches the large-diameter portion B1 of the camshaft S from both sides in the diametrical direction with a small clearance, and an engagement groove 104 that engages with the pin P.
The engaging portion 106 and the center 44 are integrally provided. This drive member 100 has a shaft 108. It is attached to the main body 98 by a link 110 and a shaft 112, and the rotation of the drive member 100 about the shaft 108 and the rotation of the link 110 about the shaft 112 combine to rotate the camshaft S in all directions perpendicular to the axis of the camshaft S. , that is, all radial movements are allowed, but three stops 114, 116 fixed to the body 98
and 118 define its movement limit.

These stops 114, 116', 118 are connected to the drive member 1 by projections 120, 122 and 124, respectively.
It also plays a role in preventing 00 from rising from the surface of the main body 98.

Next, the operation will be explained.

In FIG. 2, when the grinding work of cycle (3) is completed, the movable rests 58 of the three-point rests 28 and 30 are retracted from above the fixed rests 64 and 66, and the positioning member 42 of the axial positioning device 38 is retracted from above the fixed rests 64 and 66. is in a state where the heart axis 24 is also in a retreated state.

In this state, with the camshaft S, the pin P engaged with the engagement groove 104 of the drive member 100, and the center hole A1 engaged with the center 44, the rests 28, 30
．． Place it on top of 32 and 34. Subsequently, the center shaft 24 is advanced to fit the center 46 into the center hole A2, and the camshaft S is pressed against the center 44. As a result, the camshaft S is temporarily positioned, so when the hydraulic cylinder 94 of the axial positioning device 38 is actuated to move the positioning member 42 forward, its tip fits between the stepped surfaces Di and D2. do.

Next, the heart axis 24 is moved backward, and the three-point rest 28 and the
0 hydraulic cylinder 72 is operated to press the movable rest 58 against the journal portions J2 and J5 of the camshaft S. As described above, the pressing force at this time is a constant value determined by the elastic force of the compression coil spring 62.

As described above, the camshaft S is accurately positioned in the radial direction by the rest device 36 including the 2+11i1 three-point rests 28 and 30 and the two two-point rests 32 and 34, and the camshaft S is accurately positioned in the radial direction by the axial positioning device 38. The position of is now determined.

Subsequently, when the work spindle 22 starts rotating, the rotation is transmitted to the cam shirt S by the engagement of the drive member 100 of the drive device 40 and the pin P of the camshaft S. The movement necessary for grinding the cam profile is given to the camshaft S by the action of the mask cam 12 (see Fig. 1) and the grinding roller 16 as the work spindle 22 rotates. Cam profile grinding can be performed by bringing the cam portion corresponding to the movement at the time into contact with the grinding wheel 2° rotating at high speed.

゛ If the grinding of all the cam parts C1 to C8 is completed 5, then the grinding wheel 20 and the camshaft S are separated, the movable rests 58 of the three-point rests 28 and 30 are retracted, and the positioning device 3B is positioned. By retracting the member 42, the cam shirt (S) can be removed, and one cycle of grinding work is completed.

As is clear from the above description, in this grinding device, the centers 44 and 46 are used as temporary positioning means when attaching the camshaft S, but do not perform any function during machining, and do not perform any function on the drive device. 40 is also a floating type and does not have the function of regulating the position of the camshaft in either the radial direction or the axial direction. camshaft S
The radial positioning of is carried out by a rest device 36 with two three-point rests 28 and 30 and two two-point rests 32 and 34, and the axial positioning is carried out by means of mutually opposite stepped surfaces DI. , D2 by an axial positioning device 38 having a positioning member 42 that fits between the positions D2 and D2.

The camshaft S is connected to each cam portion C1 by the rest device 36.
Since it is supported in the vicinity of C8 to C8 with high accuracy and with a sufficient restraint force, run-out does not occur even if the grinding efficiency is improved by increasing the feed speed of the grindstone 20.
Sufficient machining accuracy can be maintained. Moreover, drive device 4
0 does not require positioning the camshaft S not only in the radial direction but also in the axial direction, and simply transmits the rotation of the work spindle 22 to the camshaft S, so a simple structure is sufficient, and the chuck is a floating type. The structure is simpler compared to the case where

Although one embodiment of the present invention has been described in detail above, this is literally an illustration, and the present invention should not be interpreted as being limited to this embodiment. For example, the drive device may be any device that can transmit the rotation of the work spindle while allowing movement of the camshaft S in the radial direction, and the members that position the camshaft S in the axial direction may also be used in the eleventh and first
As shown in FIG. 2, it is also possible to use a positioning member 132 that engages with the large diameter portion B of the camshaft S through an engagement groove 130 and performs axial positioning. It is not necessary to always engage two planes, and it is also possible to perform axial positioning by engaging another positioning member 1llil per plane. Furthermore, the positioning member does not necessarily have to engage with the workpiece through linear movement, but can also engage through rotational movement, in other words, through movement in a direction perpendicular to the axis of the workpiece. All you have to do is make them engage. Furthermore, it is also possible to engage the positioning member with the workpiece by utilizing the movement of the workpiece when attaching the workpiece to the grinding device, without moving the positioning member.

Although not illustrated in detail, it is of course possible to implement the present invention in various modifications and improvements based on the knowledge of those skilled in the art without departing from the scope of the claims.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of a cam grinder which is an embodiment of the present invention. FIG. 2 is an enlarged plan view (partially shown) of the main parts of the cam grinder. FIG. 3 is a cross-sectional view taken along line 11-11 in FIG. 2, and FIG. 4 is a cross-sectional view taken along line IV-IV. FIG. 5 is a sectional view taken along the line ■-■ in FIG. FIG. 6 is a cross-sectional view taken along line Vl--Vl in FIG. 2, and FIG. 7 is a cross-sectional view taken along line ■-■ in FIG. Figure 8 is ■- in Figure 2.
■It is a cross-sectional view, and Figures 9 and 10 are the 8th
It is a TX-IX and XX sectional view in a figure. 1st
FIG. 1 is a partially cross-sectional view of another embodiment of the device of the present invention, and FIG. 12 is a cross-sectional view showing xn-x in FIG.
It is an n cross-sectional view. 10: Swinging member 12: Master cam 14 spring 16: Combination roller 20: Grindstone 22:
Work spindle 24: Shinshin axis 2B, 30: 3-point rest 32, M
: Two-point rest 36: Rest device 38: Axial positioning device 40 Nidrive device 42.132: Positioning member 58: Movable rest 62: Compression coil spring ″′ .94: Hydraulic cylinder 100 drive member 104: Engagement groove 11o: Link 11.4, 116.118: Stosoba Applicant Toyota Motor Corporation Toyota Machinery Co., Ltd. 0 Taku 10Z GANO+ 1Q8110 112

Claims (2)

[Claims] (1) An apparatus for grinding a shaft-shaped workpiece by rotating the workpiece and bringing the outer peripheral surface of the workpiece into contact with the outer peripheral surface of a rotary grindstone, the apparatus comprising at least one (3 points of (Iit) a rest device that includes a rest and supports the workpiece in at least two axially spaced circular cross-sectional parts so as to be rotatable around the axis and movable in the axial direction; a drive device that rotates the workpiece by engaging with a portion radially away from the axis of one end of the workpiece while allowing radial movement; The workpiece is engaged with two mutually opposite planes formed at right angles to the axis at positions separated from each other in a state that allows rotation of the two planes about the axis, thereby preventing movement of the workpiece in the axial direction. and a substantially blocking axial positioning device. (2) The axial positioning device has a width slightly narrower than the interval between two stepped surfaces formed opposite to each other on the workpiece, and is immovable in the axial direction of the workpiece. Claim 1, comprising: a positioning member provided; and a drive device for fitting the positioning member between the two stepped surfaces by moving the positioning member in a plane perpendicular to the axial direction of the workpiece. The grinding device according to item 1.