JPH0160363B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chuck device for holding and clamping a workpiece, and its purpose is to increase the supporting rigidity of the workpiece within the chuck and to ensure a clamping state that can sufficiently withstand heavy cutting or high-speed cutting. The aim was to improve machining accuracy.

Conventionally, when cutting the journal part of a crankshaft, as shown in Fig. 1, the journal parts 1J to 5J and the pin parts 1P to 4P have different axial positions, and the balance weight BW protrudes. , since it is not possible to carry in or out of the chuck from the direction of the spindle axis,
A radial opening is provided in a part of the outer periphery of the chuck bodies C1 and C2, and one end of the crankshaft W is carried in and out from a direction perpendicular to the spindle axis and supported at the center 4 in the chuck, and a reference metal 19 is provided.
Positioning clamp member 20 in contact with a to 19c
Clamp the pin part 2P with the front side journal parts 1J, 2J protruding from the chuck body C2 for machining the front side journal parts, and the rear side journal parts 3J, 4J, 5J protruding from the chuck body C1 for machining the rear side journal parts. It is being processed. In this case, the crankshaft W is deflected between the supporting points of the positioning clamp part and the center support part in the chuck due to the cutting resistance reaction force, which not only causes a decrease in machining accuracy but also causes an obstacle in high-speed and heavy cutting. I was getting used to it.

The present invention has solved these conventional problems, and its gist is to provide a clamp mechanism with three-point support at approximately the midpoint between the positioning clamp part and the center support part in the chuck, and to improve the support rigidity. The present invention provides a chuck device with improved performance.

Embodiments of the present invention will be described below with reference to FIGS. 2 to 5. Reference numeral 1 denotes a chuck body, which is fixed to a main shaft 3 rotatably mounted on a head stock 2. As shown in FIG. 2, this chuck main body 1 has an opening 21 formed in a part of its outer periphery, and a workpiece, that is, one end of the crankshaft W, is carried in and carried out from the direction A perpendicular to the spindle axis through this opening 21. I'm starting to do that.

Furthermore, inside the chuck body 1, there is a reference metal 19a that the pin portion 2P abuts, and a reference metal 19b, 1 that the balance weights BW on both sides of the pin portion 2P abut.
9c, and a positioning clamp member 20 that presses and clamps the pin 2P is provided so as to be movable forward and backward in the radial direction. It also has a center 4 concentrically with the main shaft 3 that is inserted into a center hole in the end face of the crankshaft W to be supported.

In the above configuration, the present invention provides a clamping section (hereinafter referred to as an auxiliary clamping section) using a three-point support mechanism at approximately the midpoint between the positioning clamp section (hereinafter referred to as the main clamp section) provided by the positioning clamp member 20 and the support section provided by the center 4. It has been established.

Namely, reference numerals 5a, 5b, and 5c are clamp members of the auxiliary clamp section, which are provided on the chuck body 1 so as to be movable in the radial direction orthogonal to the main shaft axis. The forward and backward movement of the clamp members 5a, 5b and the clamp member 20 of the main clamp section is as follows:
This is accomplished by camshafts 15 and 17 that extend vertically through the main shaft 3 and are connected to the ram 12 that moves forward and backward through the cylinder 13. The clamp members 5a and 20 refer to a camshaft 15 connected to the ram 12 via a link 14.
The clamping member 20 and the camshaft 1
5 is engaged with the wedge surface engaging portion 16a, and the clamp member is engaged with the camshaft 15 through the wedge surface engaging portion 16a. One clamp member 5b is connected to the ram 2 and the connecting shaft 2.
It engages with the camshaft 17 connected by 2 through a wedge surface engaging portion 18. The clamp members 5a and 5b are located on the loading/unloading side of the crankshaft W from the opening 21, and are provided with wedge surface engaging portions 16b and 18 so that the amount of backward movement thereof is made larger than the outer diameter of the journal portion. It is set. The clamp member 5c that is not located on the loading/unloading side of the crankshaft W is the clamping member 5 on the loading/unloading side.
There is no need to move backwards as in a and 5b, and the fourth
As shown in the figure, locking and unlocking are performed by a locking device using a plunger mechanism. This plunger mechanism locking device is installed in each of the clamp members 5a, 5b, and 5c, and the mechanism will be explained using the clamp member 5a in FIG. 3 as a representative.

An inclined engagement surface 8 is formed on the rear end surface of the clamp member 5a, and a wedge body 6 that engages with this inclined engagement surface 8 is provided within the chuck body 1 so as to be movable forward and backward in the direction of the main shaft axis. 7, it is always pressed in the forward direction (clamping direction). A projection 11 that protrudes radially from the outer peripheral surface of the chuck body 1 is fixed to the rear end of the wedge body 6, and is a pressing member that is moved forward and backward by a wedge lock release cylinder 9 fixed to the end face of the headstock 2. 10, and when the pressing member 10 moves backward, the wedge body 6 is moved in the backward direction (unclamping direction) via the protrusion 11 by compressing the spring 7.

Next, the operation of the device of the present invention will be explained.
In the state before the crankshaft W is carried into the chuck, the clamp member 20 of the main clamp part and the clamp member 5a of the auxiliary clamp part are moved back greatly in the radial direction due to the retreat of the camshaft 15 due to the retreat of the ram 12. Also, the clamp member 5 of the auxiliary clamp part
b is also in a largely retreated position in the radial direction due to the retreating movement of the camshaft 17. Further, the wedge lock release cylinder 9 moves the pressing member 10 backward, and the wedge body 6 is moved back through the protrusion 11 to bring it into an unclamped state.

In this state, the crankshaft W is carried in through the opening 21 of the chuck body 1 which is stopped at a fixed position, and is supported on the center 4, and the pin portion 2P is
is brought into contact with the reference metal 19a and the balance weight BW is brought into contact with the reference metals 19b and 19c, and the ram 12 is moved forward. As a result, the camshafts 15 and 17 move forward, and the clamp member 20 of the main clamp section moves forward in the radial direction and presses the pin section 2P to press each reference metal 19.
a, 19b, and 19c to position and clamp. At the same time, the clamp members 5a and 5b of the auxiliary clamp section also move forward in the radial direction and come into contact with the journal section 1J. Thereafter, the wedge lock release cylinder 9 is operated forward to release the wedge 6 from its backward movement (unclamped state) by the pressing member 10. Therefore, the wedge body 6 moves forward due to the pressing force of the compressed spring 7, and comes into contact with the inclined engagement surface 8 of each clamp member 5a, 5b, 5c, as shown in FIGS. 3 and 4. , clamp members 5a, 5b,
5c is placed in a clamped state to restrict its backward movement.

The above explanation is for processing the rear journal parts 3J, 4J, and 5J in FIG.
When processing the front journal portions 1J, 2J, each clamp member 5a, 5b, 5c clamps the journal portion 4J with the chuck C2.

As described above, according to the device of the present invention, since the auxiliary clamp member supports three points approximately at the midpoint between the positioning clamp part that clamps the pin part of the crankshaft and the center support part, the crankshaft inside the chuck is supported at three points. Support rigidity is significantly improved, the crankshaft is prevented from deforming due to cutting resistance reaction force, and high-speed, heavy-duty cutting can be performed with high precision.

Moreover, in the present invention, among the auxiliary clamp members, the auxiliary clamp member on the loading/unloading side of the crankshaft is configured to have a larger backward movement amount than the outer diameter of the journal part, so even if the auxiliary clamp member is provided inside the chuck. This has the advantage that it does not pose any problem in the conventional work of carrying in and out the crankshaft from the chuck in a direction perpendicular to the spindle axis.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the clamped state in a conventional general chuck device, Fig. 2 is a front view of the device of the present invention, Fig. 3 is a sectional view taken along the line of Fig. 2, and Fig. 4 is a sectional view taken along the line of Fig. 2. FIG. 5 is a sectional view taken along the line of FIG. 3. 1... Chuck body, 2... Headstock, 3... Main shaft, 4... Center, 5a, 5b, 5c... Clamp member, 6... Wedge body, 7... Spring, 8...
Inclined engagement surface, 9... Cylinder for wedge clamp release, 10... Pressing member, 11... Protrusion, 12...
Ram, 15...Camshaft, 17...Camshaft, 19
a, 19b, 19c... Reference gold, 20... Clamp member.

Claims (1)

[Claims] 1. A positioning clamp in which the crankshaft is carried in and out from a direction perpendicular to the axis of the spindle within a chuck body fixed to a freely rotatable main shaft, and a pin portion of the crankshaft supported at the center of the chuck is provided inside the chuck. In a chuck device that clamps the crankshaft at three points approximately halfway between the positioning clamp section and the center support section, three auxiliary clamp members are provided that can move back and forth in the radial direction and support the journal section of the crankshaft at three points. A chuck device characterized in that, among the clamp members, an auxiliary clamp member on the loading/unloading side of the crankshaft has a retreating amount larger than the outer diameter of the journal portion.