JPS6146384A - Holding device for turbine wheel of friction welding machine - Google Patents

Abstract

PURPOSE:To hold a turbine wheel without adjusting phase and make centering at high accuracy by so constituting the holding device that when a projected polygonal shaft part of turbine head side is fitted in a square hole of a receiving member, the small diameter part of backside of the turbine always corresponds to a holding click for centering. CONSTITUTION:Number of angles of the square hole 9 of the receiving member 10 of the holding device is set to ten pieces, and on the other hand, number of holding clicks 26 of a collet 25 is set to its half, that is, five pieces. Accordingly, by forming the number of blades in a turbine wheel T, number of small diameter parts T6, and number of angles of projected polygonal shaft part T2 are to ten respectively, when the projected polygonal shaft part T2 is fitted to the square hole 9 of the receiving member 10 at the time of installing the turbine wheel T, holding clicks 26 of the collet 25 and small diameter parts T6 of the turbine wheel T always correspond to each other irrespective of the position, and mounting work is made easy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a friction welding machine for joining a turbine wheel and a shaft of an automobile turbocharger, and more particularly to a friction welding machine for joining a turbine wheel and a shaft of an automobile turbocharger. Relating to a gripping device.

(Prior Art) Conventionally, a turbine wheel and a shaft in a turbocharger are generally joined by friction welding. Figures 3 and 4 are J! ! This shows a general turbine wheel T before friction welding, and the end surface of the shaft S shown in FIG. 5 is friction welded to the end surface of the short cylindrical portion T1 of this turbine wheel T.

In the conventional turbine wheel gripping device, rotational torque and thrust during friction welding are handled by a receiving member having a bottomed square hole that fits into the protruding polygonal shaft portion T2 on the head side of the turbine wheel T. For centering, the large diameter part T3 (blade tip surface) on the back side of the turbine is ground or turned in advance to achieve a certain level of accuracy, and then the rolled bushing is secured using a three-way jaw chuck. The safest and most reliable method was to grasp the object through the handle.

Incidentally, if centering and gripping of the turbine wheel is to be carried out at a location other than the large diameter portion T3 of the blade described above, for example, it is possible to grip the outer edge portion T4 of the curved blade or by forming a stepped portion T5 on the back side of the turbine. Possible methods include a method of gripping this stepped portion T5, and a method of gripping the short cylindrical portion T1, which is the joint portion with the shaft on the back side of the bottle. However, in the method of gripping the outer edge portion T4, it is difficult to grip the outer edge portion T4 without a special chuck since the outer diameter dimension gradually changes. In addition, in the case of the method of gripping the stepped portion T5, it is necessary to make the jaws of the chuck overhang to avoid interference with the large diameter portion of the turbine wheel T, which weakens the rigidity of the jaws and makes it difficult to center. In addition to deteriorating the accuracy, the claws require a large opening/closing stroke, which makes it extremely troublesome to attach and detach the turbine wheel T. However, the stepped portion T5 is originally a meaningless point, and due to the weight Since it cannot be made very large (the practical limit is 1#l1lI), there is a risk that it may come off the jaw and cause a chuck failure. Furthermore,
In the method of gripping the short cylindrical part T1, not only does the amount of overhang of the claws become larger than in the case of gripping the stepped part T5, but since the claws are closer to the friction welding area, the claws may interfere with the flash that occurs during in-welding. The problem is that it is easy to cause trouble.

Therefore, conventionally, the large diameter portion T3 on the back side of the turbine described at the beginning has been selected as a preferred location for gripping for centering.

By the way, it is common for bin wheels to be manufactured using a precision casting method such as the lost wax method, but when using this manufacturing method, there is a radial groove in the insert diameter of the blade wheel shape body made of wax. It is easy for a protruding burr to appear on the surface of the turbine wheel, and if the turbine wheel is cast with this burr still attached, the burr will naturally appear in the turbine wheel product. Therefore, if you use sand vapor or the like to remove this debris during the waxing stage, there will be variation in the amount of protrusion in the radial direction of the filling diameter part, and this result will be directly reflected in the product. If a large diameter part of a product with such variations is to be gripped during friction welding, two or three blades will be gripped, causing deformation or breakage of the blades and deteriorating centering accuracy. .

(Problems to be Solved by the Invention) From the above, conventionally, the turbine wheel and the shaft were rubbed together! When welding, the large diameter part of the blade of the cast turbine wheel is machined such as grinding or turning, including deburring, to achieve the desired accuracy, and then the large diameter part is gripped. The reality is that this is happening. However, machining each turbine wheel as a preliminary process solely for friction welding is extremely wasteful and expensive.

Considering the above circumstances, the small diameter part T6 (trough between 1 and 1) on the back side of the turbine is suitable as a centering part, which is stable in terms of accuracy at the stage of the cast product, which is a rough shape material, and does not cause flashing. It is believed that there is. However, the protruding polygonal shaft portion T2 of the turbine wheel T is generally formed into a shape that fits a hexagonal or dodecagonal standard tool due to the tools required for assembly, and on the other hand, the number of blades of the turbine wheel is, for example, 10. Toga1
In most cases, the number of angles does not match the number of angles of the above-mentioned convex polygonal shaft portion T2, such as one piece. Therefore, for example, in a turbine wheel where the convex polygonal shaft part T2 is dodecagonal and the number of blades is 10, the small diameter part T2 on the back side of the turbine
If you try to grip 6 with 10 equally divided claws, you can only grip it in a certain phase.

That is, when the turbine wheel is casually inserted into the gripping device, the protruding polygonal shaft portion T2 may not fit into the receiving member of the gripping device, or the ten claws may not fit into the small diameter portion T2.
6 may not be met, resulting in a significant deterioration of workability.

In view of the above-mentioned problems, it is a technical object of the present invention to provide a gripping device for a turbine wheel of a friction welding machine that is capable of accurately and stably gripping a turbine wheel and has good workability. By the way.

(Means for Solving the Problems) In order to achieve the above-mentioned problems, the present invention provides a turbine wheel and a shaft for a turbocharger to J! ! In a gripping device for a turbine wheel when performing friction welding,
While centering and gripping the small diameter part on the back side of the turbine with the same number of gripping claws as the number of blades or half the number of blades, It is configured to be received by a receiving member having a square hole with a bottom that can be fitted into the protruding polygonal shaft portion. .

(Function) Since the present invention is configured as described above, when the turbine wheel is inserted into the gripping device, when the protruding polygonal shaft portion is fitted into the square hole of the receiving member, the back side of the turbine The small diameter part always corresponds to the gripping claw for centering. That is, according to the gripping device of the present invention, it is possible to grip the turbine wheel at any position without adjusting the phase of the turbine wheel, and moreover, highly accurate centering can be performed.

(Example) Hereinafter, an example of the present invention will be specifically described based on the drawings.

As shown in FIG. 1, a first base plate 2 and a second base plate 3 are fixed to the machine base 1 of the turbine wheel gripping device, and the first base plate 2 has a cylindrical shape. A chuck outer 5 having a tapered portion 4 on the inner circumferential surface of the front end is fixed thereto, and a central rod 7 extending concentrically within the cylindrical hole 6 of the chuck outer 5 is fixed to the second base plate 3.
is fixed. Note that the central rod 7 and the chuck outer 5 are connected to each other by a pin 8 on the rear side thereof. At the center, on the front end surface of the rod 7 is a protruding polygonal shaft portion T2 (in this embodiment, 1
A receiving member 1 having a square hole 9 that can be fitted with a rectangular hole 9
0 is fixed via a spacer 11. That is,
Rotational torque during friction welding is received by the receiving member 10, and thrust force is received by the spacer 11.

In the cylindrical hole 6 of the chuck outer 5, a piston 12 is formed approximately at the center of the central rod 7.
Also, front and rear slides 1 are provided on both sides of the piston 12.
3.14 is fitted so as to be movable in the axial direction, and both slides 13.14 are integrally formed on the front slide side and fixed via a cylindrical part that slides on the outer periphery of the piston. At the front and rear of the piston 12, the cylinder deformation 15.16 formed by the central rod 7 and the front and rear slides 13.14 is connected to a sealing O-ring 17 provided on the piston 12 and the front and rear slides 13.14. Seals 18 and 19 provided respectively, and both slides 13.
They are sealed by a sealing O-ring 20 provided on the joint surface of the central rod 7, and hydraulic oil is supplied to and discharged from them through oil holes 21 and 22 provided through the central rod 7. . Note that 23 is a guide bin provided on the chuck outer 5, and is attached to the front slide 1.
3 engages with an axial groove 24 formed on the outer periphery of the slide 13, 14 to prevent the slide 13, 14 from rotating and to guide the axial movement.

Further, a collet 25 having a gripping claw 26 at the front end is arranged on the front side of the cylindrical hole 6 of the chuck outer 5, and the rear end of the collet 25 is connected to the front slide 1.
It is fixed to the front of 3.

The collet 25 and the gripping claws 26 are divided into five equal parts in the circumferential direction as shown in FIG.
It is set so that every other small diameter portion T6 on the back side of the grip is gripped. That is, this embodiment is directed to a turbine wheel T having ten blades and a decagonal convex polygonal shaft portion T2. Further, the collet 25 is made of a spring material, and the outer circumferential surface of the thick part on the front side is a tapered surface corresponding to the tapered part 4 of the chuck outer 5, so that the chuck outer 5 is attached to the slide 13.14. It is opened and closed by moving back and forth. In FIG. 1, 27 is a clamp for the shaft S, and 28 is a positioning stopper.

This embodiment is constructed as described above, and therefore, when pressure oil is supplied to the rear cylinder chamber 16 through the oil passage hole 22, the collet 2 is
5 moves backward (moves to the right in FIG. 1), the holding force by the tapered portion 4 of the chuck outer 5 is released, and the gripping claws 26 move outward together with the collet 25 due to the restoring force due to the elasticity of the collet 25. Turbine wheel T
Release the grip on the small diameter portion T6.

Furthermore, when pressure oil is supplied to the front cylinder 15 through the oil passage hole 21, the collet 25 moves forward (moves to the left in FIG. 4 causes the gripping claws 26 to move inward together with the collet 25, so that every other small diameter portion T6 of the turbine wheel T is gripped by the gripping claws 26.

Now, in this embodiment, the number of square holes 9 of the receiving member 10 is 10.
On the other hand, the number of gripping claws 26 of the collet 25 is set to five, which is half of the number of gripping claws 26. Therefore, the factors in the turbine wheel T, that is, the number of small diameter portions T6 and the number of angles of the convex polygonal shaft portion T2, are set to five. - By forming 10 pieces each, when the turbine wheel T is attached to the gripping device, when the protruding polygonal shaft portion T2 is fitted into the square hole 9 of the receiving member 10, it is possible to determine in which position it is fitted. Even if there is colette 25
The gripping claws 26 of the turbine wheel T and the small diameter portion T6 of the turbine wheel T are sure to correspond to each other. In other words, since the installation position of the turbine wheel T with respect to the gripping device is not specified, the installation work is extremely easy.Moreover, the accuracy is stable at the stage of the cast product, which is a rough shape material, and the output of Paris is stable. Since the small diameter portion T6, which is not present, is gripped and held, the centering accuracy is also improved.

Therefore, in order to further improve the centering accuracy, it is more effective to grip the small diameter portion T6 with the same number of ten gripping claws 26, but on the other hand, as each gripping claw 26 becomes thinner, there is a possibility that the strength will decrease. However, if this is taken into account and carefully set, it is possible to use the same number of gripping claws 26 as the small diameter portion T6. Further, in this embodiment, the turbine wheel gripping device has been described in which the number of blades and the number of angles of the convex polygonal shaft portion T2 are set to 10, but the gripping device is not limited to this. This can be applied by forming the number of small diameter portions T6 in T and the number of angles of the protruding polygonal shaft portion T2 to be the same number, and in that case, the number of blades of a practical turbine wheel T is 8 to 14. Since this is common, in carrying out the present invention, it is desirable to set an even number within this range.

(Effects of the Invention) As described above, the present invention provides a gripping device for a friction welded turbine wheel, in which the small diameter part on the back side of the turbine, which is accurately stable at the stage of a rough profile, is used as the centering part. By gripping the device, it is possible to perform high-precision centering without the need for preliminary machining, which was indispensable in conventional devices, and the cost required for preliminary machining can be reduced.Moreover, the present invention This eliminates the need for phasing when attaching the turbine wheel to the gripping device, thereby facilitating the attachment and improving workability.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a cross-sectional view, FIG. 2 is a front view of the chuck part, FIG. 3 is a perspective view from the head side of a turbine wheel to be friction welded, and FIG. The figure is a perspective view of the turbine wheel from the rear side, and FIG. 5 is a perspective view of the shaft. 1... Machine base 5... Chuck outer 7... Center O-rad 9... Square hole 10... Receiving member 12... Piston 13. 14... Slide 15.16 Cylinder to 25.・Colette
26...Gripping claw T...Turbine wheel T2
...Protruding polygonal shaft part T6...Small diameter part

Claims (1)

[Claims] A device for gripping a turbine wheel when friction welding a turbine wheel and a shaft for a turbocharger, in which the small diameter part on the back side of the turbine is centered and gripped with gripping claws of the same number or half the number of blades; A convex polygonal shaft portion having the same number of angles as the number of blades formed on the turbine head side is supported by a receiving member provided with a bottomed square hole that can be fitted into the convex polygonal shaft portion. A gripping device for a turbine wheel of a friction welding machine, characterized in that the device is configured to receive the turbine wheel of a friction welding machine.