JPS5935735B2 - Temporary fixing method and device for thin-walled workpieces - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention facilitates precision machining of thin-walled workpieces that are prone to distortion by accurately fixing them on a reference seat while preventing the occurrence of distortion. The present invention relates to a method and device for temporarily fixing a thin-walled workpiece, which can be used to temporarily fix a thin-walled workpiece.

Thin-walled workpieces, such as plate-shaped thin-walled parts such as internal combustion engine case covers, are likely to be distorted by external forces. When fixing with a fixing device, it is generally not easy to fix the workpiece without causing distortion.

When machining a workpiece that is fixed in a strained state, the machining accuracy decreases, making it extremely difficult to obtain a highly accurate product. By the way, in the past, there is no satisfactory temporary fixing device for thin-walled workpieces. For example, an example will be explained first with reference to FIGS. 1 and 2. Four reference seats 2 are fixed in correspondence with the four corners, and brackets 3 are provided protrudingly on the surface of the jig plate 1 at positions corresponding to the respective reference seats 2. The fulcrum arm 4 supported by
The central portions of clamp arms 5 whose base ends are pivotally supported by piston rods 7 of clamp cylinders 6 on jig plate 1 are pivotally supported.

In such a device, when the workpiece W is a part with low rigidity such as a thin-walled part, each clamp cylinder 6
Unless the operations of the clamp arms 5 and 5 are completely synchronized, the workpiece W in the part of the clamp arm 5 that operates late when clamping the holding part of the workpiece W will lift up, pushing and bending the workpiece W as a whole. I ended up having to temporarily fix it in the current state. Therefore, for example, as in the conventional example shown in FIG. A piston rod 11 of a clamp cylinder 14 on a fixed frame 13 erected on a fixed wall 12 has an integral single clamp arm 10 .
However, in such a device, the clamp arm 10 straddles the entire workpiece W, which greatly restricts the machining work on the workpiece W, and also This makes it difficult to attach the W to the reference seat 9 or to remove it from the reference seat 9.

In view of the above-mentioned circumstances, this invention was developed to allow easy installation and removal of the workpiece, and to fix the workpiece without causing distortion that would impede machining accuracy. The main object of the present invention is to provide a method and device for temporarily fixing a thin-walled workpiece, which is easy to operate, can reliably fix the workpiece, and has a simple configuration.

Hereinafter, one embodiment of the present invention will be explained with reference to FIG. The preliminary seat 17 is connected to the jig plate 15 and the corresponding reference seat 16, respectively.
It passes through the jig plate 15 in a direction perpendicular to the jig plate 15 so as to be slidably connected thereto.

Each preliminary seat 17 has a jig plate 15 and a corresponding reference seat 16.
Instead of penetrating through the jig plates 15, they may be slidably passed through only the jig plates 15 in the vicinity of the corresponding reference seats 16. The base end portions of each reserve seat 17 are integrally connected to each other by a synchronization plate 18 on the back side of the jig plate 15, and this synchronization plate 18 is connected to the It is fixed to a spring rod 22 which is constantly receiving the spring force of a spring 21. Each reserve seat 17 normally protrudes elastically to a higher position than the seat surface of the corresponding reference seat 16, and
When the seat surface of each reserve seat 17 is pressed and moved against the elastic force to a position where it does not protrude beyond the seat surface of the corresponding reference seat 16, the seat surface of all reserve seats 17 simultaneously moves to the corresponding reference seat 16. It is configured to be pressed and moved to a position that does not protrude beyond the seat surface of the seat 16. Although only one set is illustrated in FIG. 4 as an example, there are two brackets 2 on the surface of the jig plate 15 near each reference seat 16.
3 protrudes, and the center portion of a clamp arm 25 is pivotally supported at the distal end portion of a fulcrum arm 24 supported by each of these brackets 23.

The pressing surface formed at the tip of each clamp arm 25 faces the seating surface of the corresponding reference seat 16, and the base end of each ramp arm 25 is arranged for each clamp arm 25. The piston rod 27 of a clamp cylinder 26 is fixed from the through hole of the jig plate 15 to the back surface thereof. Each clamp cylinder 2
6 is separated by a piston 28 into a first hydraulic chamber 29 on the free end wall side of the clamp cylinder 26 and a second hydraulic chamber 30 on the piston rod 27 side. The clamp cylinder 26 is configured to operate through the introduction and discharge of hydraulic oil to and from 29 and 30. The hydraulic oil sucked from inside the oil tank T by the pump P and sent under pressure is transferred to an oil path 31, a low pressure reducing valve 32, and an oil path 33.
The water is sent to the high-pressure/low-pressure switching valve 35 via the oil passage 34, and is also directly sent to another boat of the high-pressure/low-pressure switching valve 35 via the oil line 34.

The hydraulic oil exiting the high-pressure/low-pressure switching valve 35 is sent to the directional switching valve 38 via an oil passage 36 and a check valve 37. Directional switching valve 38
The second boat communicates with the oil tank T via the oil passage 41, the third boat communicates with the first hydraulic chamber 29 via the oil passage 39, and the fourth boat communicates with the oil tank T via the oil passage 40. 2nd through
It communicates with the hydraulic chamber 30 of. With the above structure, when the workpiece W is to be attached to the temporary fixing device, the high pressure/low pressure switching valve 35 is switched to the left side, and the directional switching valve 38 is switched to the left end position, and then the operation is performed. For oil, there is a low pressure reducing valve 32, an oil line 33, a high pressure-low pressure switching valve 35, and an oil line 3.
6. The hydraulic oil in the first hydraulic chamber 29 flows through the check valve 37, the directional control valve 38, and the oil passage 40 into the second hydraulic chamber 30, and the hydraulic oil in the first hydraulic chamber 29 flows through the oil passage 39, the directional control valve 38, and the oil passage 40. Since the oil is discharged to the oil tank T through the passage 41, the piston 28 moves toward the first hydraulic chamber 29, and the pressing surface of the clamp arm 25 separates from the seating surface of the reserve seat 17 accordingly. In this state, each holding portion of the workpiece W can be freely set between the seating surface of the preliminary seat 17 and the pressing surface of the clamp arm 25. Next, when the directional control valve 38 is switched to the right end position, the hydraulic oil flows into the first hydraulic chamber 29, and the hydraulic oil in the second hydraulic chamber 30 flows through the oil passage 40, the directional control valve 38, and the oil passage. 41 to the oil tank T, the piston 28 moves toward the second hydraulic chamber 30, and the pressing surface of the clamp arm 25 moves toward the reserve seat 176.

At this time, the low pressure reducing valve 32 maintains the pressure of the hydraulic oil sent to the first hydraulic chamber 29 below a certain value, so the pressing surface of the clamp arm 25 presses the reserve seat 17 against the elastic force. The holding portion of the workpiece W is elastically held in a fixed position in harmony with the elastic force of the reserve seat 17 without being moved to the rear limit until the workpiece W is reached. Therefore, in this state, the workpiece W is preliminarily and elastically connected to the preliminary seat 17 and the clamp arm 2.
5. Next, when the high pressure-low pressure switching valve 35 is switched to the right position, the hydraulic oil is transferred to the low pressure reducing valve 3.
Since high pressure oil flows into the first pressure chamber 29 without passing through 2, the piston 28 is moved to the powerful second hydraulic chamber 30, and the pressure surface of the clamp arm 25 is pressed against the reserve seat 17.
By pressing and moving the workpiece W against the elastic force, the holding part of the workpiece W is pressed onto the reference seat 16, and in this state, the workpiece W is surely pressed and held between it and the reference seat 16. do. When the machining work on the workpiece W is finished and the workpiece W is to be removed from the temporary fixing device, the directional control valve 38 is switched to the left end position to allow hydraulic oil to enter the second hydraulic chamber 30. When the pressing surface of the cranzo arm 25 is separated from the reference seat 16 and the reserve seat 17, the workpiece W can be freely removed from the temporary fixing device.

In the above embodiment, the spare seat 17 is configured to constantly receive the elastic force of the elastic spring 21.
1, as shown by the chain line in FIG. 4, a low pressure circuit 42 with a pressure reducing valve interposed between the oil passage 31 connected to the pump P and the cylinder chamber of the explosive device 20 is connected, and the low pressure flowing through the circuit 42 is connected. The resilient rod 22 may be pressed by oil.

As described above, according to the present invention, after each of the holding parts at a plurality of locations on the workpiece is preliminarily and elastically clamped between the seating surface of the preliminary seat and the pressing surface of the clamp arm, the workpiece is The workpiece is moved toward the seat surface of the reference seat against the elastic force of the reserve seat, and finally the workpiece is simultaneously seated on the reference seat in the correct posture and securely pressed and fixed. , it is easy to attach and remove the workpiece, and the machining work on the workpiece is also easy, and when the workpiece is fixed, there is no distortion in the workpiece that would impede the machining accuracy, and the operation is easy. The present invention provides a method and device for temporarily fixing a thin-walled workpiece, which is simple, can reliably fix the workpiece, and has a simple configuration.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an example of a conventional temporary fixing device, Fig. 2 is a longitudinal sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is a schematic diagram showing another example of a conventional temporary fixing device. FIG. 4 is an explanatory cross-sectional view of the main part of the temporary fixing device according to the present invention.

Claims (1)

[Claims] 1. By applying a relatively small preliminary driving force to the clamp arms 25 disposed at a plurality of locations, each holding portion at a plurality of locations on the workpiece W is fixed to a plurality of corresponding standards. The seating surfaces of a plurality of spare seats 17 elastically projecting to a higher position than the seating surface of the seat 16 and each of the clamp arms 2
After the workpiece W is preliminarily and elastically clamped between the corresponding pressing surfaces of the clamp arms 25, a driving force larger than the preliminary driving force is applied to each of the clamp arms 25. The workpiece W is moved toward the seating surface of the corresponding reference seat 16 against the elastic force of each preliminary seat 17, and finally the workpiece W is simultaneously seated on each reference seat 16 in an accurate posture. A temporary fixing method for thin-walled workpieces that securely presses and fixes thin workpieces. 2. A plurality of reference seats 16 for holding the workpiece W at a plurality of locations, and seating surfaces of the reference seats 16 that are arranged corresponding to the plurality of reference seats 16 and usually correspond to each of the reference seats 16. A plurality of reserve seats 17 elastically protrude at a higher position than the above, and the seat surface of each reserve seat 17 does not protrude beyond the seat surface of the corresponding reference seat 16 against the elastic force. When pushed to the position, all spare seats 1
a synchronizing plate 18 that integrally connects the plurality of reserve seats 17 to each other so that the seat surfaces of the reference seats 17 are simultaneously pressed and moved to positions where they do not protrude beyond the seat surfaces of the corresponding reference seats 16; They are arranged corresponding to the plurality of reference seats 16, and each has a pressing surface that presses the workpiece W, and the clamp cylinder 26 synchronously moves the pressing surface to the following three positions. a first position that maintains a sufficient distance between the seat surface of the preliminary seat 17 and the holding portion of the workpiece W to be freely put in and taken out;
The pressing surface holds the holding portion of the workpiece W against each of the preliminary seats 1.
a second position in which each preliminary seat 17 is preliminarily and elastically held between the seat surface of the reference seat 17 by using the elastic force of the preliminary seat 17; 16 to a position where the holding portions of the workpiece W do not protrude beyond the seat surfaces of the reference seats 16, and press each holding portion of the workpiece W onto the seat surface of each reference seat 16 to securely press and hold the workpiece W. A temporary fixing device for a thin-walled workpiece, comprising a clamp arm 25 that can selectively take the following positions. 3. In the temporary fixing device for a thin-walled workpiece according to claim 2, each of the reference seats 16 is fixed on the surface of the jig plate 15, and each of the preliminary seats 17 is fixed to the surface of the jig plate 15. 16, each of which passes through the jig plate 15 in a slidable manner, and the proximal end of each preliminary seat 17 is elastically ejected by an ejection device 20 on the back side of the jig plate 15. A temporary fixing device for thin-walled workpieces, which is interconnected by the synchronization plate 18. 4. In the temporary fixing device for thin-walled workpieces as set forth in claim 3, each of the preliminary seats 17 passes through the jig plate 15 and the corresponding reference seat 16 so as to be freely slidable. Temporary fixing device for thin-walled workpieces.