JPH079290A - Workpiece clamping method and clamping jig preparing device - Google Patents

Abstract

PURPOSE:To cope with a workpiece of any shape without restriction to a machining surface of the workpiece and to prevent distortion and deformation of the workpiece due to clamping force. CONSTITUTION:A clamping jig preparing device 20 is provided with a displaceable upper frame 26, a lower frame 32 abutting on the upper frame 26, a liquid introducing tube 44 for injecting a liquid W in a chamber 34, a hole part 54 for adjusting the liquid W introduced into the chamber 34 to a quantity including a calculated freezing expanding quantity, and a pressing member 52 for pressing a workpiece 10 housed in the chamber 34 toward a lower frame 32 side. The device 20 is also provided with a base member 38 for positioning a bottom surface part of the workpiece 10 flush with an upper surface part of the lower frame 32, and a freezing chamber 56 for freezing the liquid W injected into the chamber 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of clamping a work and a clamp jig making apparatus for fixing the work on a jig stand or a pallet by immersing the work in a liquid and freezing it when cutting the work. Regarding

[0002]

2. Description of the Related Art Conventionally, when cutting or drilling a work, a clamping device for fixing the work is required. Here, FIG. 8 shows a plan view of a clamp device according to a conventional example.

This clamp device 2 is clamped by a tightening bolt 4 and is clamped by a clamp arm 6a to 6c which rotates within a predetermined range.
On the jig table 8 (or pallet) (3 in the figure
Are provided). In the clamp device 2, the tip ends of the clamp arms 6a to 6c are cylinder blocks,
The work 10 is fixed to the jig base 8 by rotating the work 10 such as a cylinder head so as to come into contact with the peripheral edge of the work 10 and tightening the tightening bolts 4.

In this case, the clamp arms 6a-6c
The work 10 may be deformed due to the pressing force of. When the deformed work 10 is processed in this state,
There is a disadvantage that a high-precision machining cannot be performed due to a positional deviation between the work 10 and the machining tool. Also, work 1
When processing a thin portion of 0, since the thin portion cannot be completely fixed, the portion vibrates.
There is an inconvenience that so-called chattering occurs and processing defects occur.

Further, there is an inconvenience that a plurality of clamp arms 6a to 6c arranged on the jig base 8 become obstacles to restrict a processing portion. In this case, it is possible to fix the work 10 again and process it, but the number of working steps is increased and it is complicated.

Furthermore, a clamp device corresponding to various shapes of the work 10 is required, and a plurality of clamp devices must be prepared according to the types of works, which is very expensive.

On the other hand, as shown in FIG.
When drilling is performed, burrs 14 are generated on the end faces of the holes drilled by the drill 12, and thus deburring work is required after processing. In addition, there is also a problem that cutting powder generated during processing enters the non-processed portion.

Therefore, as a technical idea for solving the above-mentioned inconvenience, Japanese Patent Laid-Open No. 143930/58 discloses a freezing chuck method for freezing and fixing the entire work.
In this freezing chuck method, a work is accommodated in a cavity of a freezing frame, and a liquid is injected into the cavity to freeze the entire liquid including the work, thereby fixing the work.

[0009]

However, in the prior art disclosed in Japanese Patent Laid-Open No. 58-143930,
Since machining is performed with the work fixed in the cavity, there is the inconvenience that the machined surface of the work is limited to only one surface of the upper surface of the open cavity.

The present invention has been made in order to overcome the above-mentioned inconvenience, and it is possible to deal with a work of any shape without restricting the working surface of the work, and at the same time, to fix the work by the clamping force. An object of the present invention is to provide a clamp method for a work and a clamp jig creating apparatus capable of preventing distortion, deformation and the like and performing highly accurate processing.

[0011]

In order to achieve the above-mentioned object, the present invention provides a step of positioning and accommodating a work to be processed in a frame composed of an upper frame and a lower frame, and a freeze expansion amount. A step of introducing the expected amount of liquid into the frame, a step of freezing the liquid, and a step of leaving the work in one frame via the frozen liquid and removing the other frame, It is characterized by having.

In this case, it is preferable that the processed portion of the work is arranged on the other frame side to be removed from the opening of the one frame in which the work is left.

Further, according to the present invention, an upper frame and a lower frame that define a chamber for accommodating a work and can be separated from each other, a liquid injection means for injecting a liquid into the chamber, and a liquid injected into the chamber. And a freezing means for freezing.

Further, an opening is defined on the upper frame, and the opening defines the amount of liquid injected by the liquid injection means.
It is preferable to adjust the freeze-expansion amount to an expected amount.

Furthermore, the inner wall surfaces of the upper frame and the lower frame are
It is preferable that the chamber is formed so as to be inclined so that the volume of the chamber is gradually reduced from one frame to the other frame.

Further, it is preferable to have a positioning member for positioning the processed portion of the work so as to be arranged on the side of the other frame which is removed from the opening of the one frame where the work is left.

Further, it is preferable that a hole for processing the work is defined in the lower frame.

[0018]

In the work clamping method and the clamping jig making apparatus according to the present invention, the work to be processed is positioned and accommodated in the frame including the upper frame and the lower frame. Next, after injecting an amount of the liquid, which is expected to be frozen and expanded, into the frame to freeze the liquid, either the upper frame or the lower frame is removed, and the work is fixedly held in the other frame. Then, the exposed predetermined part of the work is processed. At that time, if the processed portion is on the side of the remaining frame, either the upper frame or the lower frame is used for fixing the work, and the other frame is removed. At the time of processing, the work is held in the solidified liquid, and the processing tool performs the processing operation by using the block body containing the liquid as a processing target.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a workpiece clamping method and a clamping jig making apparatus according to the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIGS. 2 and 3, the clamp jig preparing apparatus 20 according to the first embodiment has one end of a piston rod 22 which is displaced in the directions of arrows X and Y under the driving action of a piston (not shown). An upper frame 26 that is connected to the upper plate 26 via a guide plate 24 and is displaceably provided;
An upper surface portion 30 that abuts the bottom surface portion 28 is formed, and basically includes a lower frame 32 that functions as a pallet and is held on a line (not shown). Between the upper frame 26 and the lower frame 32, the bottom surface portion 28 and the upper surface portion 30 contact each other to define a chamber 34 for accommodating the work 10 therein (see FIG. 3). By providing a seal member on the bottom surface portion 28 and the top surface portion 30 which are in contact with each other, it is possible to prevent the liquid W from leaking from the contact portion. Further, the chamber 34 defined by the upper frame 26 and the lower frame 32 is formed into a substantially truncated pyramid shape, and is formed so as to open from the upper frame 26 toward the lower frame 32. In addition, the work 1 in the present embodiment
A cylinder head is used as 0.

The lower frame 32 is formed with a recess 36 which is a part of the chamber 34, and the bottom surface of the recess 36 defines the work 10.
A plurality of base members 38 for positioning and mounting the are fixed. The base member 38 has a large diameter portion 38 having a different diameter.
a and a small diameter portion 38b, the large diameter portion 38a and the small diameter portion 38b are integrally connected via a screw 39. In this case, the flange portion 41 of the large diameter portion 38a has the frozen liquid W when the upper frame 26 is displaced, as described later.
Is held, the frozen liquid W is left on the lower frame 32 side. An interposition member 40 for adjusting the height of the work 10 is provided between the base member 38 and the work 10. By providing the base member 38 and the interposition member 40, the bottom surface portion of the work 10 can be flush with the upper surface portion 30 of the lower frame 32 or higher.

A hole 42 is formed in the upper surface of the upper frame 26, and the liquid introducing tube 4 is screwed into the hole 42.
4 are connected. A guide plate 24 is fixed to the upper surface of the upper frame 26, and a locking member 46 for locking one end of the piston rod 22 is fixed to the upper surface of the guide plate 24. The guide plate 24
The upper frame 2 when the upper frame 26 is displaced in the X and Y directions.
There is provided a guide rod 48 that supports 6 and guides the lower frame 32 so as to appropriately abut. The upper frame 26 is provided with a pressing member 52 that engages with the spring member 50 through the hole 43 formed in the upper surface.
Further, on the side surface portion of the upper frame 26, a hole portion (opening portion) for allowing the excess liquid W of the liquid W introduced from the liquid introduction tube 44 to flow out is defined. In this case, the freeze expansion amount of the liquid W injected in advance is calculated from the volume of the work 10 and the height A from the bottom surface portion 28 to the hole 54 is set so that the work 10 is completely immersed in the liquid W. Set to a predetermined value. Furthermore, in the present embodiment, a freezing chamber 56 that functions as a freezing means for freezing the liquid W introduced into the chamber 34 is provided (see FIG. 3). The freezing means is not limited to the freezing chamber 56, and may be, for example, the upper frame 26 and the lower frame 3.
The liquid W may be frozen by connecting a cooler (not shown) to 2 and directly cooling the upper frame 26 and the lower frame 32.

Clamp jig making device 2 according to the first embodiment
0 is basically configured as described above,
Next, a method of making a clamp jig by this device will be described.

First, as shown in FIG. 1, the work 10 roughly formed by casting or the like is used as a recess 36 of the lower frame 32.
It is positioned and placed on the interposition member 40 disposed inside. In this case, since the upper end surface of the interposition member 40 is formed flush with the upper surface portion 30 of the lower frame 32, the bottom surface portion of the work 10 is set flush with the upper surface portion 30. .

Next, the piston rod 22 is displaced in the arrow X direction under the driving action of a cylinder (not shown), whereby the upper frame 26 is displaced in the arrow X direction (see FIG. 2). At the displacement end of the upper frame 26, the bottom surface portion 28 of the upper frame 26 and the upper surface portion 30 of the lower frame 32 come into contact with each other to define a chamber 34 inside. In this case, the pressing member 5 provided on the upper frame 26
2 holds the work 10 by pressing the upper surface of the work 10 downward under the action of the elastic force of the spring member 50. Upper frame 2
6, while the work 10 is accommodated in the chamber 34 between the lower frames 32, these are moved into the freezing chamber 56 (see FIG. 3).

Next, the liquid W is introduced into the chamber 34 from the liquid supply source (not shown) through the liquid introduction tube 44.
The introduced liquid W is stored in the chamber 3 having a substantially truncated pyramid shape.
4 is gradually stored from the bottom surface portion 28, penetrates into the hole portion defined in the work 10, and becomes the state shown in FIG. In this case, the amount of the stored liquid W is determined by the preset predetermined height A of the hole 54 of the upper frame 26. In addition,
The height A is set to a position where the work 10 is completely immersed when the liquid W is frozen. Excess liquid W is hole 5
4 is discharged to the outside.

After the above-mentioned conditions are set, the clamp jig making device 20 is cooled in the freezing chamber 56. As a result, the liquid W in which the work 10 is immersed is frozen, and the whole work 10 is fixed and held by the liquid W solidified by the freeze expansion. The shape of the frozen liquid W is a truncated pyramid shape that is substantially the same as that of the chamber 34 (see FIG. 4). Liquid W
After freezing, the upper frame 26 is displaced in the direction of the arrow Y under the driving action of a cylinder (not shown) to be separated from the lower frame 32 by a predetermined distance. At that time, the inner wall surface of the lower frame 32 is contracted toward the upper frame 26 side, and the large-diameter portion 3 of the base member 38 is formed.
Since the flange portion 41 is provided on the 8a, the liquid W frozen via the inner wall surface of the lower frame 32 and the flange portion 41 can be held on the lower frame 32 side. As a result, the frozen liquid W is in a state of being integrally connected to the lower frame 32 without being separated from the lower frame 32. Further, since the upper frame 26 is expanded to the lower frame 32 side, the mold releasing work thereof can be performed very easily. Since the work 10 is held and fixed in the frozen liquid W as described above, the work 10 can be reliably fixed to the lower frame 32 regardless of the shape of the work 10. Further, since the work 10 is entirely fixed uniformly via the frozen liquid W, it is possible that the work 10 is deformed by the extreme pressing force of the clamp arms 6a to 6c as in the conventional case. Can be prevented. The clamp jig is created as described above.

As shown in FIG. 4, the work 10 held in the liquid W solidified in this way is cut by a cutting tool such as a drill 60 and a milling cutter 62 with the other surface except the bottom surface as the working surface. Processing work can be performed. At this time, by using cutting water as the liquid W that is solidified and holds the work 10, the work 10 can be suitably cut without damaging the cutting edges of the drill 60 and the milling cutter 62. Therefore, the work 10
The unprocessable surface of is only the bottom surface. In this case, for example,
Even if a thin portion of the work 10 is processed by using the milling cutter 62, since it is fixed and held by the solidified liquid W, the thin portion can be processed without vibrating and causing so-called chattering. it can.

On the other hand, as shown in FIG. 5, similarly to the above, the work 10a held by the frozen liquid W is fixed to the lower frame 32, and a horizontal hole is formed in the work 10a in a substantially horizontal direction. When it is installed, it is possible to preferably perforate without generating the burr 14 as shown in FIG. This is because the end surface of the hole formed by the drill 60 is held by the solidified liquid W. Further, during processing, cutting powder is prevented from entering the non-processed portion.

Next, another clamping method of the present invention will be described in relation to the clamp jig making apparatus according to the second embodiment. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 6, the clamp jig making device 70 basically comprises an upper frame 72 and a lower frame 74 which are provided so as to be relatively displaceable. A chamber 80 is defined by the recess 76 of the upper frame 72 and the recess 78 of the lower frame 74. A seal member (not shown) is preferably provided at a portion where the upper frame 72 and the lower frame 74 are in contact with each other in order to prevent the liquid W from leaking from the chamber 80.

On the bottom surface of the concave portion 76 of the upper frame 72, projections 82a to 82 for pressing the work 10 downward.
d is formed. A recess 78 larger than the shape of the work 10 is defined in the lower frame 74, and projections 84a and 84b for positioning and supporting the work 10 are provided on the bottom surface of the recess 78. A plurality of holes 88a to 88c for inserting a drill when processing the workpiece 10 are formed in the side surface portion 86 of the lower frame 74 that is inclined and reduced in diameter.
(Working hole) is defined, and bulging portions 90a and 90b bulging toward the work 10 side are formed at the ends of the side surface portion 86.
Is provided. The bulging portions 90a and 90b are for holding the frozen liquid W on the lower frame 74 side.

Further, a hole portion 92 for introducing the liquid W into the chamber 80 is defined at a substantially central portion of the upper frame 72.
Here, the lower frame 74 is fixed on a base (not shown), while the upper frame 72 is provided so as to be displaceable in the directions of arrows X and Y under the driving action of a displacement means (not shown). The clamp jig creating device 70 is arranged in the freezer compartment 56.

Clamp jig making device 7 according to the second embodiment
0 is basically configured as described above, and a method of creating it will be described next.

First, in a state in which the work 10 positioned through the protruding portions 84a and 84b is accommodated in the recess 78 of the lower frame 74, from the hole portion 92 communicating with the chamber 80, for example, a liquid introducing tube or the like. The liquid W is introduced through the liquid injection means. The introduced liquid W is gradually stored in the recess 78 of the lower frame 74, and finally the whole work 10 is immersed. The liquid W is introduced until the upper surface of the work 10 is filled. In this case, a space is defined in the concave portion 76 above the work 10 so that the liquid W may swell from the upper surface of the work when frozen.

Next, after the above setting, the freezer compartment 5
The liquid W stored in the chamber 80 is frozen via a freezing means such as 6. Therefore, the work 10 is held in the frozen liquid W and is fixed to the lower frame 74 via the frozen liquid W. In such a state, the upper frame 72 is displaced in the arrow Y direction and separated from the lower frame 74. In this case, as shown in FIG. 7, since the work 10 is surrounded and held by the side surface portion 86 of the lower frame 74 through the frozen liquid W, the clamping force for holding the work 10 is further increased. Will be strengthened.

Therefore, it is possible to perform a cutting process on the work 10 held in the frozen liquid W by using a processing device such as a drill 60 and a milling cutter 62 as shown in FIG. When machining from the side surface of the work 10, the hole portions 88 a defined in the side surface portion 86 of the lower frame 74
The drill 60 may be inserted through 88c.

As described above, in the clamp jig producing apparatuses 20 and 70 according to the first and second embodiments, the entire liquid W into which the work 10 is immersed is frozen regardless of the size and shape of the work 10. The lower frame 32, 74 to the work 10
Can be fixed. Therefore, it is possible to prevent the work 10 from being distorted or deformed due to the clamping force.

[0039]

EFFECTS OF THE INVENTION According to the work clamping method and the clamping jig making apparatus of the present invention, the following effects can be obtained.

That is, the work surface of the work is not restricted, and the work can be fixed in correspondence with the work of any shape and size. Moreover, since the entire work is held and fixed by the solidified liquid,
No distortion or deformation is given to the work. Further, when the work is processed, the thin part can be fixed with the solidified liquid even if the part is thin, so that chattering does not occur, and as a result, processing defects do not occur. Furthermore, since burr does not occur, it is possible to improve work efficiency without requiring deburring work. In addition, it is possible to prevent the cutting powder from entering the non-processed portion.

As described above, it is possible to prevent various problems existing in the prior art and to perform highly accurate processing on a work.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a work is positioned on a lower frame that constitutes a clamp jig creating apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which an upper frame and a lower frame constituting the clamp jig creating device according to the first embodiment of the present invention are separated from each other.

FIG. 3 is a cross-sectional view showing a state in which a liquid is introduced into a room in the clamp jig creating device shown in FIG.

FIG. 4 is a cross-sectional view showing a state in which the upper frame is separated from the lower frame and the work contained in the frozen liquid is fixed to the lower frame in the clamp jig manufacturing apparatus shown in FIG.

FIG. 5 is a cross-sectional view showing a state in which a horizontal hole is drilled in a horizontal direction of a work fixed to a lower frame which constitutes the clamp jig creating apparatus shown in FIG.

FIG. 6 is a schematic configuration diagram showing a clamp jig creating device according to a second embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a state in which a work contained in frozen liquid is fixed to a lower frame that constitutes the clamp jig creating device shown in FIG.

FIG. 8 is a plan view showing a clamp device according to a conventional example.

FIG. 9 is a cross-sectional view showing a state in which a horizontal hole is drilled in a horizontal direction of a work fixed to a clamp device according to a conventional example.

[Explanation of symbols]

10, 10a ... Work piece 20, 70 ... Clamp jig creating device 26, 72 ... Upper frame 32, 74 ... Lower frame 34, 80 ... Chamber 38 ... Stand member 40 ... Interposer member 44 ... Liquid introduction tube 54, 88a-88c … Hole 56… Freezer

Claims (7)

[Claims] 1. A step of positioning and accommodating a work to be processed in a frame composed of an upper frame and a lower frame; introducing a liquid into the frame in an amount that allows for the amount of freeze expansion. And a step of leaving the work in the one frame through the frozen liquid and removing the other frame, the method for clamping the work. 2. The method according to claim 1, wherein the processed portion of the work is arranged on the side of the other frame to be removed from the opening of the one frame on which the work is left. Clamping method. 3. An upper frame and a lower frame that define a chamber for accommodating a work and can be separated from each other, a liquid injecting means for injecting a liquid into the chamber, and a freezing process for freezing the liquid in the chamber. An apparatus for producing a clamp jig for a work, comprising: 4. The apparatus according to claim 3, wherein an opening is defined in the upper frame, and the opening adjusts the amount of the liquid injected by the liquid injecting means to an amount that allows for the amount of freeze expansion. A device for creating a work clamp jig. 5. The apparatus according to claim 3 or 4, wherein the inner wall surfaces of the upper frame and the lower frame are inclined so that the volume of the chamber is gradually reduced from one frame to the other frame. An apparatus for creating a clamp jig for a work, which is characterized by being formed. 6. The apparatus according to any one of claims 3 to 5, wherein the processed portion of the work is arranged closer to the other frame than the opening of the one frame in which the work is left. An apparatus for creating a clamp jig for a work, which has a positioning member for positioning. 7. An apparatus according to claim 3, wherein a hole for processing the work is defined in the lower frame.