JPH0540908Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a clamp device for fixing a workpiece onto a base surface. For more details,
The present invention relates to a clamping device suitable for fixing a workpiece, such as a cylinder head, which has a recessed portion such as an intake/exhaust port on its side surface.

(Prior Art and its Problems) As is well known, machining and assembly work on a workpiece such as a cylinder head is performed with the workpiece positioned and fixed on a workpiece table by a clamp device. A clamping device for fixing a workpiece onto a base surface includes one or more sets of clamp members, moves these from a retracted position toward the workpiece on the base, and uses these to secure the workpiece onto the base. It is designed to be fixed to These clamping members are moved between their retracted and clamped positions by a pivoting movement, usually about a vertical or horizontal axis. However, such a device that moves the clamp members by pivoting requires a large amount of space for the movement of the clamp members. Therefore, it has the disadvantage that it cannot be installed in a workstation where installation space is limited.

An example of a device that overcomes these drawbacks is the device described in Japanese Utility Model Application Laid-Open No. 62-78237. In this device, L-shaped clamp members are lowered and a workpiece is fixed between the horizontal portions of their upper ends and a workpiece table. However, this device has a drawback in that it cannot process the portion of the upper surface of the workpiece that is held down by the clamp member.

In view of the above-mentioned conventional problems, the purpose of the present invention is to provide a clamping device that can reduce the space for moving the clamping member and minimize the portion of the workpiece that cannot be processed by the clamping member. The aim is to realize this.

(Means for Solving the Problem) In order to achieve the above object, the clamp device of the present invention reciprocates in a straight line in the direction approaching and away from the work in conjunction with the movement of the lifting member that moves up and down on the work table. It has a movable clamp member. In addition, this clamp member can engage with the side surface of the workpiece when it approaches the workpiece,
Furthermore, when this engaged state is formed, the clamp member is pressed against the work table by the pressing member.

More specifically, the clamp device according to the present invention includes a base, an elevating member that is movable up and down with respect to the base, a cam plate provided on the elevating member and having an inclined cam groove, and a cam plate provided on the elevating member and having an inclined cam groove. and a clamp member provided close to the cam plate. A protruding portion is provided on the lower surface of the clamp member so as to protrude downward, and this protruding portion is slidably engaged with the sliding groove of the base. The clamp member is further provided with a pin that engages with the cam groove of the cam plate. A pressing member is provided on the work side of the base so as to be positioned above the clamp member and presses the clamp member from above. The cam groove of the cam plate has a shape that moves the clamp member forward in the direction of the workpiece when the elevating member descends, and the sliding groove of the base moves the clamp member forward to a position where it can engage with the workpiece. The protruding portion of the clamp member has a length such that the protruding portion of the clamp member comes off from the sliding groove when the clamp member is pressed. Further, the elevating member is provided with a pressing member that presses the holding member toward the clamp member from above when the elevating member is lowered.

(Function) The clamp device having this configuration is installed, for example, in a work station for machining cylinder heads.
In this case, clamp devices are installed at each of the four corners of the cylinder head placed on the workbench so that the tip of the clamp member can engage with the inner peripheral surface of the intake and exhaust port formed on the side surface of the cylinder head. Make it. When the clamp device is driven to move the lifting member, the clamp member starts approaching the work in conjunction with this movement, and its tip is inserted into the intake/exhaust port of the cylinder head and engages the inner peripheral surface. It will be in a state where it matches. When the clamp member engages with the cylinder head in this manner, the clamp member is pressed against the base surface by the pressing member. As a result, the clamp member presses the inner circumferential surface of the intake/exhaust port toward the work table, thereby fixing the cylinder head to the work table. After processing such as end face cutting is performed on this fixed cylinder head,
Contrary to the above, the elevating member, the pressing member, and the clamping member move to release the cylinder head from being fixed to the work table.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In the embodiments shown in FIGS. 1 to 6, the present invention is applied to a work station for machining cylinder heads.

Overall Structure of Work Station As shown in FIG. 6, a positioning jig 3 is installed on the top surface of the bed 2 of the work station 1. A workpiece 6 placed on a pallet 5 is conveyed by a carrier 7 along a rail 4 formed on the upper surface of this jig 3. This conveyance by the carrier 7 is performed by a so-called "lift and carry" method. Palette 5 by carrier 7
When the pallet 5 is carried into the processing position, the pallet 5 is
It is pressed from above by a positioning rod 8 placed above against a positioning pin 9 placed on the top surface of the jig. As a result, the pallet 5 is positioned at the processing position and fixed at that position. There are four clamping devices 1 on the top of the pallet 5.
1 is installed. On the other hand, processing units 10 are installed on both sides of the positioning jig 3. These units are, for example, cylinder head end finishing machines.

Installation position of the clamping device As shown in FIGS. 1 and 2, the cylinder head 6 is disposed on the upper surface of the pallet 5 in a direction perpendicular to the conveying direction A. The cylinder head in this example is for a four-cylinder engine. Clamp devices 11-1 to 11-4 of the same structure are installed facing each other on both sides of the cylinder head, sandwiching the bore portions constituting the first cylinder on the front side and the fourth cylinder on the rear side. be. That is, each clamping device is connected to the intake port 6 of each of these cylinders.
1, 62 or exhaust ports 63, 64.

Structure of the Clamp Device The structure of the clamp device will be explained by taking as an example the clamp device 11-3 arranged facing the intake port 62 of the fourth cylinder.

As shown in FIGS. 3 to 5, the base 31 of the clamp device 11 is fixed to the upper surface of the pallet by bolt connection. A cylindrical portion 311 extending vertically is formed on the upper surface of the base 31.
The upper end of this cylindrical portion 311 is an open end,
Inside the cylinder, a rotating shaft 32 is disposed coaxially with the cylindrical portion, and its lower end is pivotally supported by a portion forming the bottom surface of the cylindrical portion. A nut portion 321 is formed at the upper end of this rotating shaft 32 and is rotatable by a nut runner (not shown). A collar 33 is attached to the outer peripheral surface directly below the nut portion 321. A cylindrical lifting member 34 is coaxially arranged around the outer periphery of the rotating shaft 32 located below the collar 33. A female thread 341 is formed on the lower inner peripheral surface of this elevating member 34, and this female thread is connected to the rotating shaft 32.
By meshing with the male thread 321 formed on the lower outer circumferential surface of the rotary shaft and rotating the rotating shaft 32, the elevating member 34 is formed along the rotating shaft by the outer circumferential surface of the rotating shaft and the inner circumferential surface of the cylindrical portion. It is possible to slide up and down within the annular groove 35. This lifting member 34
The upper part of the outer circumferential surface of is reduced inward to form an annular jaw part 342, and a horizontal connection is made between this jaw part 342 and a collar 36 fitted on the outer circumference of the upper end of the elevating member. A member 37 is held.

The upper end of a vertically arranged rectangular cam plate 38 is coupled to the tip of the horizontal connecting member 37. The lower portion of the cam plate 38 is slidably supported within a vertical groove 39 formed in the upper surface of the base 31. As can be seen from FIG. 3, this cam plate 38 is provided with a cam groove 381 of a constant width, and this groove is inclined downward from the front side F to the rear side R of the clamp device. . On the other hand, this cam plate 3
A sliding groove 40 extending horizontally from the front surface to the rear surface of the clamp device is formed in the base portion located between the lifting member 34 and the lifting member 34 described above. A clamp member 41 is arranged therein, which can be reciprocated in the horizontal direction. As shown in FIG. 5, this clamp member 41 has a sliding pin 42 horizontally attached to the central part of its side surface, and the tip of this pin 42 is passed through a horizontal groove made in a blind plate 43. Then, the cam groove 381 on the cam surface
It is slidably inserted inside. Further, a depression 411 is formed on the upper surface of the clamp member, and a protrusion 412 that projects downward is formed on the lower surface on the front side thereof. The height of the sliding groove is set to such a height that the clamp member forming the protrusion can slide from the front end to the rear end, and the main body of the clamp member can slide at the rear end. It has been narrowed to a certain height.

On the other hand, a vertically movable holding pin 44 is disposed on the base portion forming the upper wall on the front side of the sliding groove 40, and this pin is moved upwardly by the recess 411 of the clamp member. As shown in FIG. It also protrudes upward. A pin holding portion 371 formed on the horizontal connecting member is positioned above the protruding upper end of the pin.
When the above-mentioned elevating member finishes descending along the rotation axis, this pin pressing portion 371 presses the upper end of the pin 44, and thereby the clamp member is pushed downward by the pin 44. .

By appropriately setting the length and inclination of the cam groove of the cam plate, when the elevating member is in the uppermost position, the pin of the clamp member is positioned behind the cam groove as shown in Figure 3. When the pin is located at the end and the elevating member is at the lowest position, the pin is located at the front end of the cam groove as shown in FIG. In addition, by appropriately setting the stroke amount of the clamp member, as shown in FIG. Insert it into the intake port of the head so that its tip surface engages with the opening edge of the intake port. Further, in this state, the rear surface of the protrusion formed on the lower surface of the clamp member is positioned at the lower front edge of the sliding groove.

(Operation) Next, the operation of the clamp device of this example configured as described above will be explained.

First, as shown in FIG. 6, a cylinder block 6 placed on a pallet 5 is carried by a carrier 7 to a processing position. After being carried in, a positioning rod 8 is lowered from above the pallet 5 and the pallet is fixed in that position.

Next, the clamping device 11 on the pallet
As shown in the figure, the elevating member 34 is in the uppermost position, and therefore the clamp member 41 interlocked with this elevating member is in the retracted position. In this state, when the rotating shaft 32 is rotated by a rotating means such as a nut runner, the elevating member 34 screwed onto the outer circumferential surface starts to descend. As a result, the cam plate 38 also begins to descend. When the cam plate descends, the pin 42 in the cam groove 381 formed in the cam plate slides toward the front side F along this cam groove. That is, the clamp member 41 starts moving horizontally toward the front side.

After this, when the elevating member 34 reaches the lowest position, the pin 42 in the cam groove reaches its front end, and the clamp member 41 is moved to its lowest position on the front side F as shown by the imaginary line in FIG. It becomes a prominent state. In this state, the front end surface of the clamp member 41 engages with the opening edge of the intake port of the cylinder head. At the same time, the vertical pin 44 is moved to the holding part 3 of the horizontal connecting member.
71. Therefore, the clamp member 41 moves slightly downward, as shown by the solid line in FIG. 1, and presses the cylinder block against the pallet surface. In this way, the cylinder block is fixed onto the pallet by the clamping member 41. Thereafter, processing units 10 located on both sides approach the fixed cylinder block 6, and predetermined processing is performed on this cylinder block.

After machining is completed and the machining unit is evacuated,
The clamp member is retracted to its retracted position by an operation opposite to that described above. That is, the rotating shaft 32 is rotated in the opposite direction, and the elevating member 34 starts rising. As a result, the clamping member 41 is attached to the vertical pin 4.
4, and as the cam plate 38 rises, it begins to move toward the rear side R. Lifting member 3
4 reaches its uppermost position, the clamp member 41 also reaches its retracted position, as shown in FIG. Thereafter, the pallet carrying the machined cylinder blocks 6 is released from its fixation and transported again to the next work station by the carrier 7. Thereafter, a pallet carrying cylinder blocks to be machined is transported to the machining position in the manner described above.

In the above embodiment, a device for clamping a cylinder head has been described, but the device of the present invention can be similarly applied to a workpiece having a recessed portion similar to an exhaust port on the side surface.

(Effects of the Invention) As described above, in the clamp device of the present invention, the movement of the workpiece clamping member and the workpiece clamping operation are performed in conjunction with the lifting and lowering movements of the lifting member. Therefore, compared to a conventional device in which the clamp member is rotated and moved to the clamp position, the space required for moving the clamp member can be reduced. In addition, in the device of the present invention,
The workpiece is fixed on the workbench by engaging the clamp member with the recessed part on the side of the workpiece, so the surface of the workpiece is covered by the clamp member, making it difficult to process that part. The negative effects of not being able to do so can be minimized.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a workpiece clamping state of a clamp device according to an embodiment of the present invention, Fig. 2 is a plan view showing the positional relationship between the clamp device of Fig. 1 and the cylinder head, and Fig. 4 is a plan view of the device in FIG. 1, FIG. 5 is a sectional view of the part taken along the - line in FIG. 4, and FIG. 6 is the entire workstation. FIG. 2 is a schematic configuration diagram showing the configuration. 5...Pallet, 6...Cylinder head, 11
-1 to 11-4...clamp device, 31...base, 32...rotating shaft, 34...lifting member, 37...
...Horizontal connection member, 38...Cam plate, 381...Cam groove, 41...Clamp member, 42...Sliding pin, 44...Pin.

Claims (1)

[Scope of utility model registration request] a base; an elevating member provided to be movable up and down with respect to the base; a cam plate provided in the elevating member and having an inclined cam groove; a clamp member provided close to the cam plate; a protrusion provided on the lower surface of the clamp member so as to protrude downward and slidably engages with the sliding groove of the base; a pin provided on the clamp member and engaged with the cam groove of the cam plate; a pressing member provided above the clamp member on the work side of the base to press the clamp member from above, and the cam groove of the cam plate holds the clamp member against the work when the elevating member descends. The sliding groove of the base has a shape such that the protruding portion of the clamping member is moved out of the sliding groove when the clamping member advances to a position where it can engage with the workpiece. A clamping device having a length, the elevating member being provided with a pressing member that presses the pressing member toward the clamp member from above when the elevating member is lowered.