JPH07156032A - Clamping device - Google Patents

Abstract

PURPOSE:To miniaturize a clamping device and reduce the weight thereof by inserting a connecting rod for pressing a housing toward a base into an inserting hole and a through-hole. CONSTITUTION:Compressed air is supplied to an air pressure actuating chamber 20 when a clamping condition is switched to an unclamping condition. Then, a piston 14 is retreated backward against a clamping spring 19 and the front part of a clamping rod 13 is retreated backward to a rear side more than the front surface 6a of a housing 6. A lower form 2 is switched in up and down directions in this condition. Both side walls of a through-hole 24 provided on the clamping rod 13 are guided by a connecting rod 27 inserted into the inserting hole 25 of the housing 6. Thus, the clamping rod 13 is prevented from being rotated around an axial core and moved back and forth and straight in an axial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for clamping a fixed object such as a mold or a work.

[0002]

2. Description of the Related Art As a clamp device of this type, there is one disclosed in Japanese Patent Application Laid-Open No. 3-178744 proposed by the present inventor. This conventional technique is configured as follows.

A guide hole extending in the front-rear direction is provided obliquely downward at the center of the housing placed on the upper surface of the table in the left-right direction, and a clamp rod is inserted into the guide hole so as to be movable back and forth in the front-rear direction. On the left and right side walls of the housing,
Two bolt holes extending vertically are formed so as to penetrate therethrough. The lower screw portion of the fastening bolt inserted into each bolt hole is screwed into the female screw hole of the table, and the housing is pressed and fixed to the table by the tightening force of the two bolts. further,
Both ends of the guide pin are inserted into the left and right side walls, and the central portion of the guide pin is brought into contact with the lower surface of the clamp rod from below.

[0004]

In the prior art described above, the guide pin prevents rotation of the clamp rod around its axis and can guide the clamp rod in the axial direction. It excels in being simple. However, in the related art, the following improvements have been demanded.

Since it is necessary to provide bolt holes on the left and right side walls of the housing, the size of the housing in the left-right direction becomes large. Therefore, the clamp device becomes large and heavy. Moreover, since the housing is fixed by screwing the fastening bolts into the screw holes of the table, the mounting position of the housing in the front-rear direction cannot be adjusted. Therefore, when the size of a fixed object such as a mold changes, it is difficult to cope with the change. To solve this problem, it is conceivable to provide a plurality of female screw holes in the table in the front-rear direction. However, since the pitch of these female screw holes in the front-rear direction is limited by the root diameter of the female screw,
The housing cannot be finely adjusted to a desired position in the front-rear direction.

An object of the present invention is to make a clamping device small and lightweight. Another object of the present invention is to enable the housing to be fixed in a desired position in the front-rear direction in a finely adjusted state.

[0007]

In order to achieve the above object, the present invention has a clamp device configured as follows. For example, as shown in FIG. 1 and FIG. 2 or FIG. 3, a guide hole 11 is provided obliquely downward in a housing 6 placed on the upper surface of the base 1, and the guide hole 11 is provided on the front surface of the housing 6. 6a, the clamp rod 13 is inserted into the guide hole 11 so as to be movable back and forth in the axial direction, and the drive means G for moving the clamp rod 13 back and forth in the axial direction is provided in the housing 6, and the clamp rod 13 is provided.
A through hole 24 extending in the vertical direction in the middle of the axial direction of the
Are provided on both upper and lower sides of the through hole 24, and the guide hole 1
1 is provided with an insertion hole 25, and a fastening rod 27 that presses the housing 6 toward the base 1 is inserted between the insertion hole 25 and the through hole 24.

[0008]

The present invention operates as follows, for example, as shown in FIG. 1 and FIG. 2 or FIG. In the clamped state shown in the drawing, the clamp rod 13 is advanced downward leftward by the driving means G, and the clamp surface 23 at the tip thereof presses the clamped surface 2a of the fixed object 2 from above. The clamp release force D acts on the clamp rod 13 from the fixed object 2 described above, and the clamp release force D is received by the tightening force E of the fastening rod 27. As a result, the housing 6 is held at the initial position on the base 1. When switching from the clamped state to the unclamped state, the drive means G may be used to retract the clamp rod 13 from the clamp position shown in the upper right direction.

Through the through hole 24 formed in the clamp rod 13 during the unclamp drive or the clamp drive.
Both side walls 24c, 24c are guided by the tightening rod 27. As a result, the clamp rod 13 is prevented from rotating around the axis and is moved straight back and forth in the axial direction.

As shown in FIGS. 1 and 2 above, a nut 4 is inserted into the T groove 3 provided in the base 1 and the lower screw portion 29 of the fastening rod 27 is inserted into the nut 4. When they are screwed together, they further operate as follows. By loosening the fastening rod 27, the housing 6 can be moved back and forth along the T groove 3 to a desired position in the front-rear direction, and the fastening rod 27 can be tightened at the desired position to fix the housing 6 to the base 1. Can be fixed to. Therefore, even if the size of the fixed object 2 changes, the size change can be easily dealt with.

[0011]

【Example】

(First Embodiment) FIGS. 1 and 2 show a first embodiment.
FIG. 1A is a vertical sectional view of the clamp device. Figure 1 (B)
[Fig. 2] is a sectional view taken along the line BB of Fig. 1 (A). Figure 2
FIG. 2 is a sectional view taken along the line II-II of FIG.

A lower die 2 as an object to be fixed is placed on the upper surface 1a of the bolster 1 of the press machine, and the lower die 2 is pressed and fixed to the upper surface 1a of the bolster 1 by a clamp device. A T groove 3 is formed on the upper portion of the bolster 1 so as to extend in the front-rear direction (referred to as the left-right direction in FIG. 1, hereinafter the same). The small groove portion 3a of the T groove 3 is opened in the upper surface 1a of the bolster 1, and the nut 4 is inserted into the large groove portion 3b of the T groove 3 in a back-and-forth direction so as to prevent rotation.

A housing 6 of the clamp device is mounted on the upper surface 1a of the bolster 1 so as to be movable back and forth.
The housing 6 comprises a main body 7 and a cylinder tube 8, and the cylinder tube 8 is airtightly fixed to the rear portion of the main body 7 by a plurality of bolts (not shown).
The lower convex portion 9 of the main body 7 is fitted into the small groove portion 3a of the T groove 3. A guide hole 11 is formed obliquely downward toward the front surface 6a of the housing 6 in the center of the main body 7 in the left-right direction. The cylinder hole 12 of the cylinder tube 8 is provided coaxially with the guide hole 11 in series.

The clamp rod 13 is inserted into the guide hole 11 so as to be movable back and forth in the axial direction. The cylinder hole 12
The piston 14 is airtightly inserted into the
Is integrally formed with the clamp rod 13. A spring accommodating hole 16 is formed across the piston 14 and the clamp rod 13. A clamp spring 19 is mounted between the bottom wall 17 of the hole 16 and the end wall 18 of the cylinder tube 8. Further, an unclamping pneumatic working chamber 20 is provided between the piston 14 and the rear portion of the main body 7. The working chamber 20 communicates with a compressed air supply / discharge hole 22 through a communication hole 21. The cylinder hole 12
And piston 14, clamp spring 19 and pneumatic working chamber 20
And constitute driving means G for the clamp rod 13.

A clamp surface 23 is formed on the front portion of the clamp rod 13. The clamp surface 23 is formed substantially parallel to the clamped surface 2a of the lower mold 2.
A through hole 24 extending in the vertical direction is provided at an intermediate portion of the clamp rod 13 in the axial direction. Further, the insertion hole 2 extending in the vertical direction is provided in the central portion of the main body 7.
5 and 25 are provided so that these insertion holes 25 and 25 intersect the guide hole 11.

The above insertion holes 25, 25 and the above through hole 2
The fastening bolt 27 is inserted into the connector 4 from above. The head 28 of the bolt 27 is brought into contact with the upper surface of the body 7 from above. Further, the lower screw portion 29 of the fastening bolt 27 described above.
Is projected from the lower surface 6 b of the main body 7 and is engaged with the female screw portion 30 of the nut 4. Fastening bolt 2 above
By tightening 7, the housing 6 is pressed and fixed to the upper surface 1 a of the bolster 1 by its head portion 28.

The clamp device is used as follows. In the illustrated clamped state, compressed air is discharged from the pneumatic working chamber 20. Therefore, the clamp rod 13
Is clamped by the clamping spring 19 to the front surface 6a of the housing 6.
And the clamp surface 23 presses the clamped surface 2a of the lower mold 2 from above.

In the clamped state, when the upper mold (not shown) and the lower mold 2 are separated from each other, as shown in FIG. 1 (A), the clamp releasing force D is upward from the lower mold 2 to the clamp rod 13. Act on. The housing 6 is held at the initial position on the bolster 1 by receiving the clamping release force D by the tightening force E of the bolt 27.

When the clamp releasing force D is applied, the clamp rod 13 slightly swings in the clockwise direction by the amount of the fitting gap with the guide hole 11,
The rear lower portion M and the front upper portion N of the guide hole 11 are strongly elastically deformed. Thereby, the guide hole 1
A strong frictional force acts on the upper peripheral surface of the clamp rod 13 from the front upper portion N of No. 1, and a strong frictional force also acts on the lower peripheral surface of the clamp rod 13 from the rear lower portion M of the same guide hole 11. To work. The resultant force of these frictional forces prevents the clamp rod 13 from retracting.

Incidentally, according to the experiment, when the elastic force C of the clamp spring 19 is set to 40 kgf, the clamp rod 13 can be operated even if the clamp releasing force D is 1600 kgf which is 40 times the elastic force C. Holds in clamped position.

The inclination angle θ of the guide hole 11 is set to about 12 degrees in this embodiment. The inclination angle θ may be in the range of 5 to 20 degrees for holding the clamp rod 13 in the clamp position, and may be in the range of 5 to 15 degrees for more reliable holding of the clamp. Is preferred.

When the clamped state is switched to the unclamped state, compressed air is supplied to the pneumatic working chamber 20. Then, the piston 14 is retracted rearward and upward against the clamp spring 19, and the front portion of the clamp rod 13 is retracted rearward of the front surface 6 a of the housing 6. In this state, the lower mold 2 is vertically replaced.

The above embodiment has the following advantages. Since it is not necessary to provide bolt holes in the left and right side walls 6c, 6c of the housing 6, the thickness of the side wall 6c can be reduced to reduce the lateral dimension of the housing 6. As a result, the clamp device can be made small and lightweight.

When the unclamp drive or the clamp drive is performed, the through hole 24 provided in the clamp rod 13 is provided.
Both side walls 24c, 24c are guided by a tightening bolt 27. As a result, the clamp rod 13 is prevented from rotating around the axis and is moved straight back and forth in the axial direction. In this way, since the tightening bolt 27 can also serve as the linear guide means for the clamp rod 13, it is not necessary to provide a dedicated guide means, and the structure of the clamp device is simplified.

At the time of the unclamp drive, the front wall 24a of the through hole 24 contacts the peripheral surface of the bolt 27 to prevent the piston 14 from colliding with the end wall 18 of the cylinder tube 8. It As a result, the cylinder tube 8 can be made small and lightweight.

In the unclamped state, by loosening the bolt 27, the housing 6 can be moved back and forth along the T groove 3 to a desired position in the front-rear direction. Therefore, even if the size of the lower mold 2 is different, it is possible to easily cope with the change in size. Incidentally, in order to prevent the nut 4 from coming out of the T groove 3, the opening end of the T groove 3 is covered with a plug 33.

When the housing 6 is fixed to the bolster 1 by tightening the bolt 27, at the same time, the upper surface of the nut 4 comes into contact with the upper wall of the large groove portion 3b of the T groove 3, and the nut 4 and the T groove 3 are joined. Eliminates rattling. For this reason, the clamp rod 13 does not need to have a play stroke for absorbing the above-mentioned rattling, and the total stroke becomes small. As a result, the clamp device can be made compact and consumes less energy. Furthermore, since the fitting gap can be eliminated by tightening the bolt 27, it is not necessary to process the T groove 3 and the nut 4 with high precision, and the processing cost is low.

In the unused state where the above-mentioned clamp device is stored in a warehouse or the like, the clamp rod 13 has the clamp spring 19
Although it is projected forward by the elastic force of, the rear wall 24b of the through hole 24 contacts the bolt 27,
It is suppressed that the clamp rod 13 largely projects. Note that the clamp device can be used even when a large amount of heat is received from the bolster 1 or the lower mold 2 or in a high temperature atmosphere. That is, the clamp rod 13 is connected to the clamp spring 1
This is because the clamp can be driven by the elastic force of No. 9, so that the adverse effect of raising the working chamber to an abnormal pressure unlike the hydraulic clamp does not occur.

FIG. 3 is a longitudinal sectional view showing the second embodiment, and FIG.
[Fig. 6] is a partial view showing a modified example. In these other embodiments and modified examples, members having the same configurations as those of the above-described first embodiment will be described with the same reference numerals.

(Second Embodiment) As shown in FIG. 3, a female screw hole 37 is provided in the bolster 1, and the lower screw portion 29 of the fastening bolt 27 is screwed into the female screw hole 37. Furthermore, a pin 38 for preventing rotation is inserted into the upper surface 1a of the bolster 1 and the main body 7 of the housing 6. The other structure is the same as that of the first embodiment. In the second embodiment, it is not necessary to provide the above-mentioned T-groove, so that the bolster 1 can be processed without trouble.

(Modification) As shown in FIG. 4, a sliding shuttle member 41 is slidably supported by a front portion of the clamp rod 13 through a key 42 in the front-rear direction within a certain range.
The shuttle member 41 is formed by plating nitriding alloy steel and is elastically pressed forward by the advancing spring 43. The stopper bolt 44 prevents the shuttle member 41 from moving forward more than a predetermined amount. The stopper bolt 44 is inserted into a loose hole (not shown) provided in the shuttle member 41 and fixed to the clamp rod 13 with a screw.

The above-described embodiments and modifications can be modified as follows. The fastening rod for fixing the housing 6 to the bolster 1 includes, in place of the bolt 27, a T leg portion fitted into the T groove 3 and a cam for pressing the upper surface of the housing 6 downward. Good.

The driving means G for moving the clamp rod 13 back and forth may be one in which a clamp fluid pressure working chamber is formed on the rear side of the piston 14. Further, when the clamp spring 19 is mounted in the clamp fluid pressure working chamber and both the spring 19 and the fluid pressure are used together,
A strong clamping force can be obtained. When the clamp device is used in a high temperature atmosphere or the like, the working fluid supplied to the working chamber is preferably a gas body such as compressed air. The above-mentioned drive means G may utilize the screwing force of a screw instead of the fluid pressure cylinder.

The object to be fixed by the clamp device may be an upper mold instead of the lower mold 2 or a work or the like. The base on which the housing 6 is placed may be a lower die mounting board fixed to the upper surface of the bolster instead of the bolster of the press machine, or a fixed board or a movable board of the injection molding machine, Alternatively, it may be a table of a cutting machine or the like.

[0035]

The present invention has the following effects because it is configured and operates as described above. Since it is not necessary to provide fastening bolt holes on the left and right side walls of the housing, the thickness of the side walls can be reduced, and the lateral dimension of the housing can be reduced. As a result, the clamp device can be made small and lightweight. Further, when the unclamp drive or the clamp drive is performed, the tightening bolt can also serve as the linear guide means of the clamp rod, so that it is not necessary to provide a dedicated linear guide means for the clamp rod, and the structure of the clamp device is simplified. Become.

When the clamp rod is configured to be clamp-driven by the clamp spring, it is possible to prevent the clamped state from being released due to the leakage of the working fluid.

Further, when a nut is inserted into the T groove provided on the base and the lower threaded portion of the fastening rod is screwed into the nut, the following effects are further obtained. By loosening the fastening rod, the housing can be moved forward and backward along the T groove to a desired position in the front-rear direction, and the fastening rod can be tightened at the desired position to fix the housing to the base. Therefore, even if the size of the fixed object changes, the size change can be easily dealt with.

[Brief description of drawings]

FIG. 1 shows a first embodiment of the present invention. FIG. 1A is a vertical sectional view. FIG. 1B is a BB line of FIG. 1A.
FIG.

FIG. 2 is a sectional view taken along line II-II of FIG. 1 (A).

FIG. 3 shows a second embodiment of the present invention and is a diagram corresponding to FIG. 1 (A) described above.

FIG. 4 is a partial view showing a modified example of the present invention and corresponding to FIG. 1 (A) described above.

[Explanation of symbols]

1 ... Base (bolster), 3 ... T groove, 3b ... Large groove part, 4 ...
Nut, 6 ... housing, 6a ... front surface of housing 6,
6b ... Lower surface of housing 6, 11 ... Guide hole, 12 ... Cylinder hole, 13 ... Clamp rod, 14 ... Piston, 1
9 ... Clamping spring, 20 ... Unclamping fluid pressure working chamber (pneumatic working chamber), 24 ... Through hole, 25 ... Insertion hole, 27 ...
Fastening rods (fastening bolts), 28 ... head, 29 ... lower threaded portion, G ... driving means.

Claims (3)

[Claims] 1. A housing mounted on the upper surface of a base (1).
A guide hole (11) is provided obliquely downward in (6), the guide hole (11) is opened in the front surface (6a) of the housing (6), and the clamp rod (13) is inserted in the guide hole (11). Is inserted in the axial direction so that the clamp rod (13) can be moved back and forth in the axial direction, and a drive means (G) for moving the clamp rod (13) in the axial direction is provided in the housing (6). A through hole (24) extending in the vertical direction is provided in the portion, and an insertion hole (25) intersecting with the guide hole (11) is provided on both upper and lower sides of the through hole (24), and the insertion hole (25 ) And the through hole (24), a clamping rod (27) for pressing the housing (6) toward the base (1) is inserted, and the clamping device is characterized in that. 2. The clamp device according to claim 1, wherein the drive means (G) is provided in a cylinder hole (12) provided in series with the guide hole (11) and a tight seal is provided in the cylinder hole (12). A piston (14) inserted like a ring, a clamping spring (19) provided on the rear side of the piston (14), and an unclamping fluid pressure working chamber (20) provided on the front side of the piston (14). Configured by. 3. The clamping device according to claim 1, wherein the base (1) is provided with a T groove (3) extending in the front-rear direction,
The nut (4) is inserted into the large groove portion (3b) of the T groove (3) so as to be able to advance and retract in the front-rear direction, and the fastening rod (27) is constituted by a bolt, and the fastening rod (27) is formed. The upper part of the housing (6) is engageable from the upper side with the fastening rod
The lower screw part (29) of (27) can be screwed to the nut (4).