JP3051254B2 - Two fastening vise - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-piece vice, and more particularly, to a type in which left and right movable jaws approach a central fixed jaw to clamp a workpiece between them. The present invention relates to an improvement in technology for reducing sliding resistance from a frame acting on a movable jaw when a clamp is released.

[0002]

2. Description of the Related Art In a two-piece vise, a fixed jaw is generally provided at the center of a frame, and first and second movable jaws are provided near both right and left ends thereof. Below these, a screw shaft extending in the horizontal direction is provided through the frame so as to be rotatable and axially movable. In this screw shaft, two screw portions (reverse screws) formed apart from each other in the axial direction are screwed to nuts integral with each movable jaw.

An operation of clamping two workpieces having a dimensional difference (different in clamp width) in the two-piece tightening vice having such a schematic configuration will be described. First screw shaft
, Each movable jaw moves closer to the fixed jaw. If, for example, the first movable jaw first contacts the workpiece during this approaching movement, the nut is locked (locked) in its axial position. Therefore, the screw shaft that continues to rotate moves toward the first movable jaw due to the threaded relationship with the nut. Along with the movement of the screw shaft, the second movable jaw becomes (movement amount due to the screwing relationship with the screw shaft) + (movement amount of the screw shaft) = (movement amount of twice the movement amount of the screw shaft). The robot moves closer to the workpiece and eventually comes into contact with the workpiece.

[0004] However, in the conventional structure of the two-piece tightening vise, there is a problem when the clamp is released, particularly when there is a difference in sliding resistance when the two movable jaws are moved. For example, the first
A large sliding resistance acts on the movable jaw. Under these conditions, when the screw shaft is rotated in the second direction opposite to the previous direction, first, the first movable jaw remains stopped,
Only the second movable jaw moves away from the workpiece.
At this time, the screw shaft also moves in the same direction because of the threaded relationship with the nut of the first movable jaw. When the second movable jaw moves beyond its initial starting position by more than a defined stroke and reaches a critical position and hits the end of the frame, the second movable jaw cannot move any further. Only at this time does the first movable jaw begin to move, but since the second movable jaw moves more than the specified stroke, the total amount of movement of the first movable jaw becomes less than the specified stroke. Therefore, when the same workpiece is clamped next, a complicated operation of re-adjusting the stroke for both movable jaws becomes necessary.

In order to avoid the trouble of re-adjusting the movable jaw stroke due to the sliding resistance acting on the movable jaw, US Pat. No. 4,934,674 discloses a sliding resistance reduction in a two-piece vice. A mechanism has been proposed. In the prior-art two-clamping vise, the protrusion of the screw shaft from the frame, and in the case of the above-described conventional configuration, the protrusion on the second movable jaw side is provided with a sliding resistance reducing mechanism. is there. This sliding resistance reduction mechanism has a kind of energy storage structure (more precisely, an energy storage structure). This sliding resistance reduction mechanism is composed of two compression springs wound around the end of a screw shaft in series via a sleeve, and two compression springs, and the inner and outer springs of the two springs are wrapped and extended, and one end is framed. And a set screw that integrates the housing with a screw shaft via a sleeve. Of the two compression springs, the compression spring in the housing has one end in contact with the frame and the other end in contact with the housing. The compression spring in the frame has one end in contact with the flange formed on the frame and the other end on the flange formed on the sleeve.

In the operation of the double fastening vise to which this prior application is applied, as in the case of the conventional configuration, after the first movable jaw comes into contact with the workpiece, the second movable jaw moves the screw shaft. It moves closer to the workpiece by twice the amount of movement. At this time, since the set screw of the sliding resistance reducing mechanism has not been tightened yet, the housing and the sleeve are not integrated with the screw shaft, and the compression spring is in a free state. When the second movable jaw continues to move and approaches a predetermined distance to the workpiece (this is appropriately set in consideration of actual process conditions), when the set screw is tightened, the housing and the sleeve are connected to the screw shaft. Integrate. As a result, as the second movable jaw continues to move further, the spring in the housing is compressed and accumulates force (energy). The second movable jaw eventually comes into contact with the workpiece to perform the clamping.

When the clamp is released, the second movable jaw and the screw shaft start to move (in the direction opposite to the direction at the time of clamping), and the spring in the housing is gradually released from the compression and the accumulated force (energy) ) Is released. If the first movable jaw is stopped because the sliding resistance of the first movable jaw is large, the screw shaft moves to the second movable jaw as it is. By the movement of this screw shaft,
The spring in the frame is compressed and accumulates the axial pressing force, which overwhelms and reduces the sliding resistance acting on the first movable jaw, so that the first movable jaw also starts moving early. I do. That is, since the movements of the first and second movable jaws are started almost simultaneously, it becomes practically unnecessary to readjust the movable jaw stroke as in the prior art.

[0008]

In the case of the sliding resistance reducing mechanism of the prior application, although having the above-mentioned advantages, the size between two workpieces (of a new lot) to be newly clamped. If the difference is different from the dimensional difference between the two clamped workpieces (of the old lot), the sliding resistance must be reduced each time to adjust the position of the screw shaft in the axial direction. The operation of loosening and tightening the set screw of the mechanism is required, and the operation is inevitably complicated. Further, the structure of the sliding resistance reducing mechanism is complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sliding device capable of avoiding the trouble of re-adjusting the movable jaw stroke at the time of releasing the clamp without incurring a complicated work and a complicated structure in the two-piece tightening vise. It is to provide a dynamic resistance reduction mechanism.

[0010]

SUMMARY OF THE INVENTION For this reason, a two-piece vice according to the present invention has a rotating shaft having two oppositely threaded portions spaced apart in the axial direction on a frame for axial rotation and axial movement. On the upper surface of the frame, two movable jaws axially spaced apart from each other on both sides of the fixed jaw are screwed into the above-mentioned screw portion, and the axial resistance sufficient to reduce the maximum sliding resistance acting on the movable jaw is reduced. The gist of the present invention is that a sliding resistance reducing mechanism for elastically applying the generated radial pressing force to the rotating shaft is engaged with the rotating shaft.

[0011]

The axial resistance generated by the radial pressing force applied to the rotating shaft by the sliding resistance reducing mechanism overwhelms the sliding resistance acting on the movable jaw, so that a larger sliding resistance acts when the clamp is released. One movable jaw also starts moving early.

[0012]

1 and 2 show a first embodiment of a two-piece vice according to the present invention, in which a biasing member is provided on a braking member. In this example, the rotating shaft is constituted by the screw shaft 10, the piston, and the housing 52. In this example, the first and second pistons are separated from each other.
The pistons 54 and 56 are connected at the center by a connecting member 58. However, the connecting member 5
The piston 8 and one of the pistons may be formed integrally.
The pistons 54, 56 extend into the screw shaft 10 and are integrally connected to the screw shaft 10 at respective ends.

The housing 52 has a cylindrical structure.
It is externally inserted into the screw shaft 10 and the first and second pistons 54 and 56, and is engaged with the screw shaft 10 via a key 63 that fits into a notch 61 formed in the housing 52. A plurality of annular grooves 60 are formed on the outer periphery of the housing 52 so as to be separated from each other in the axial direction.

A bush 64 is inserted into both ends of the housing 52 by retaining rings 62, and each piston 54,
A cylinder is defined between the bush 64 and the bush 64, respectively. The connecting member 58 is formed with a through hole in the axial direction, and connects the two cylinders to each other.

A compression spring 66 is interposed between one of the pistons, the second piston 56 in the drawing, and the connecting member 58. Due to the urging action of the spring 66, a predetermined oil pressure is constantly applied via the first and second pistons 54 and 56.

The housing 52 accompanying the axial movement of the rotating shaft
In the moving range of the upper annular groove 60 (for example, near the center of the bottom surface or side surface of the frame), the frame 2 is formed with a blind hole pointing toward the outer periphery of the housing 52, and the blind hole has rigidity in this example. And a compression spring 70 that elastically presses the ball 68 toward the outer periphery of the housing. The ball 68 is a braking member according to the present invention, and the spring 70 is a biasing member. Therefore, the spring 7
By appropriately selecting 0 and / or the depth of the blind hole, an axial resistance (rotational axis) sufficient to reduce the force for pressing the ball 68 to the outer periphery of the housing 52, in other words, the maximum sliding resistance acting on the movable jaw. Can be freely adjusted. As a specific example, a screw hole penetrating the frame is formed in the pressing direction of the ball 68, a screw having the blind hole is screwed into the screw hole, and a nut is screwed into a screw protruding from the frame. By doing so, the screw may be fixed to the frame at an arbitrary position. The blind hole is preferably formed in the frame so that its center line coincides with the radial direction of the housing 52. However, the blind hole does not necessarily have to coincide.

There are various means for rotating the rotating shaft. In the illustrated example, a fastening screw 12 having a square head at the outer end is inserted into the screw shaft 10 and the screw shaft is 10 is engaged. Further, the end of the rod 16 engaged with the inner end of the tightening screw 12 is inserted into the cylinder defined by the bush 64 and the first piston 54 via the clutch 14 to control the hydraulic pressure in the cylinder. ing. As shown in FIG. 7, a cylindrical member 29 having a screw hole is fixed to the inside of the screw shaft 10 by a pin or the like.
Is screwed into. The tightening screw 12 has a flange at the end on the bar 16 side. Further, the tightening screw 12 fixes the disk 31 between the flange and the cylindrical member 29 by using the tightening screw 1.
2 so as to be non-rotatable and axially movable. A compression spring is interposed between the flange and the disk 31. A V-shaped uneven portion (not shown) is formed on the facing surface of the cylindrical member 29 and the disk 31 and is always in a fitted state by the urging force of a compression spring.

Next, the operation will be described. First, as an initial adjustment, before setting the workpiece to be clamped in the vise, it is necessary to adjust the stroke of the movable jaw according to the dimensions of the workpiece. For this purpose, the rotating shaft is rotated or moved in the axial direction. The axial movement at this time is manually performed with a force higher than the axial resistance from the braking member, that is, the resistance when the ball 68 escapes from the annular groove 60 of the housing 52.

When the initial adjustment is completed, the workpiece is set in the vise, and the movable jaw is moved by rotating the rotating shaft.
At this time, the rotating shaft rotates together with the tightening screw 12 via the clutch 14.

When one movable jaw comes into contact with the workpiece,
The rotating shaft moves toward the one movable jaw while rotating. Accordingly, the other movable jaw moves toward the workpiece by twice the moving amount of the rotating shaft. At this time, the rotating shaft is pressed against the annular groove 6 of the housing 52 against the pressing force of the spring 70.
The ball moves while pushing up the ball 68 from zero.

When the other movable jaw also contacts the workpiece,
Since the rotational load of the rotating shaft exceeds the critical load of the clutch 14, thereafter only the tightening screw 12 rotates. More specifically, since the rotating shaft is fixed in the axial direction, the disk 31 moves in the axial direction along the inclination of the uneven portion against the urging force of the compression spring, and disengages with the cylindrical member 29. . Therefore, the tightening screw 12 is screwed into the cylindrical member 29. The tightening screw 12 moves toward the piston while rotating, so that the rod 16 enters the cylinder.

The intrusion of the bar 16 increases the oil pressure in the cylinder, and the first and second pistons 54 and 56 are pressed toward the fixed jaws. These pistons 5
Since the pistons 4, 56 and the screw shaft 10 are integrally connected, each movable jaw is also pressed toward the workpiece with the movement of the piston, and the clamping is completed.

At the time of releasing the clamp, the rotating shaft is rotated via the tightening screw 12 in the direction opposite to the direction at the time of clamping. When any movable jaw does not move due to sliding resistance, the rotating shaft tends to move in the axial direction. However, since the ball 68 is engaged with the annular groove 60 in the housing 52,
Axial resistance acts on the rotating shaft. According to the present invention, since the axial resistance is set so as to reduce the sliding resistance acting on the movable jaw, the axial resistance overwhelms the sliding resistance, and as a result, the movable jaw in the stopped state slides. It starts moving against the dynamic resistance.

In the above example, the screw shaft 10, the pistons 54 and 56, and the housing 52 constitute a rotary shaft. However, the rotary shaft is formed as an integral structure without using a hydraulic booster mechanism. May be performed. An example is shown in FIG. In this case, the rotating shaft 7
Reference numeral 1 denotes two threaded portions 72 which engage with the movable jaws 6 and 8, and an annular groove portion 74 which forms a part of the sliding resistance reducing mechanism 50 therebetween.
And are integrally formed.

In each of the above embodiments, the sliding resistance reducing mechanism 50 is provided at the center of the rotary shaft. However, in addition to the above, the sliding resistance reducing mechanism 50 does not hinder the movement of the movable jaw and corresponds to the axial movement range of the rotary shaft. You may comprise in the part to obtain. For example, a rotating shaft protruding from the frame (right side in FIG. 1)
And a bracket (not shown) attached to the frame so as to face the protruding portion.

In the above example, the rigid ball 68 is used as the braking member. However, as shown in FIG. 4, a brake shoe 72 may be used instead. In this case, it is not necessary to form an annular groove in the housing 52.

In each of the above embodiments, the braking member is provided with an urging member such as a spring. However, the braking member itself may have elasticity. In the example shown in FIG. 5, a rubber ring 74 is used as a braking member,
2 and is in contact with the frame 2. In the example shown in FIG. 6, a curved leaf spring 76 is used as the braking member.
Is fixed to the frame 2 and the housing 52
Is formed with an annular groove having a cross-sectional waveform. When such a leaf spring is used, the resistance in the rotating direction with respect to the rotating shaft is reduced, so that the influence on the fastening operation is reduced.

In addition, two fastening vise as shown in FIG.
One of the two movable jaws 6 and 8 is desirably provided so as to be fixed to the frame 2 so that it can be used as an individual fastening vise. In this case, the other movable jaw can be fed at twice the speed when used as the double fastening vise, so that a single fastening vise having a high feeding speed can be configured. One specific configuration is:
The movable jaw 8 is provided with two vertically penetrating holes, and when the movable jaw 8 is moved to the leftmost side of the frame 2 (the state shown in FIG. 1), the movable jaw 8 is positioned on the frame 2 facing the two holes. Screw holes are formed on the upper surface so as to be concentric with the holes. Further, the fixing jaw 4 is fixed to the position shown in FIG. 1 with a screw. As a fixing method of the fixing jaw 4 at this time, for example, as shown in FIG. 2, the frame 2 and the fixing jaw 4 are fitted on irregularities, and two screw holes are formed in a concave groove formed in the frame. It is formed and screwed to the fixed jaw 4 via a vertically penetrating hole. When used as a single fastening vise, the movable jaw 8 is moved to the left, then a screw is inserted into each hole of the movable jaw 8 and screwed to the frame 2. Further, the fixing jaws 4 may be removed from the frame 2 by loosening the screws.
As another configuration, it is conceivable to fix the movable jaw 8 to the frame 2 via the fixed jaw 4. That is, a concave groove is also formed on the upper surface of the frame 2 in front of the movable jaw 8 at the position shown in FIG. 1 so that the fixed jaw 4 can be screwed to the frame 2 adjacent to the movable jaw 8. Further, a through hole is formed in the work clamping surface of the fixed jaw 4 in the axial direction of the screw shaft 10, and a screw hole is formed concentrically in the movable jaw 8. When using as a single fastening vise,
The fixed jaw 4 is screwed to a position adjacent to the movable jaw 8, and another screw is inserted into a through hole of the fixed jaw formed in the axial direction of the screw shaft 10 to fasten the movable jaw together. Instead of fastening the movable jaw 8 together with the fixed jaw 4, a plate may be interposed between the movable jaw 8 and the fixed jaw 4.

[0029]

According to the present invention, one of the movable jaws to which a greater sliding resistance is applied when the clamp is released also starts to move at an early stage.
There is no practical need to readjust the movable jaw stroke.
In addition, since the pressing force for reducing the sliding resistance is applied to the rotating shaft in the radial direction, it does not affect the axial movement of the rotating shaft, so even when newly clamping a workpiece having a different dimensional difference, Since the rotating shaft moves in the axial direction while the pressing force for sliding attenuating resistance is applied, complicated work such as loosening the set screw once and re-tightening at the time of clamping as in the prior art is necessary. Not taken
The work is simplified. Moreover, since the braking member is only elastically pressed against the outer periphery of the rotating shaft, the structure is extremely simple.

[Brief description of the drawings]

FIG. 1 is a partially sectional side view showing an example of a two-piece vise provided with a sliding resistance reducing mechanism of the present invention.

FIG. 2 is a partially sectional side view showing an example of the sliding resistance reducing mechanism of the present invention.

FIG. 3 is an abbreviated side view showing another example of the two-piece vice provided with the sliding resistance reducing mechanism of the present invention.

FIG. 4 is a partial sectional side view showing a main part of another example of the sliding resistance reducing mechanism of the present invention.

FIG. 5 is a partial sectional side view showing a main part of another example of the sliding resistance reducing mechanism of the present invention.

FIG. 6 is a partial sectional side view showing a main part of another example of the sliding resistance reducing mechanism of the present invention.

FIG. 7 is a sectional side view showing the internal structure of the screw shaft.

[Explanation of symbols]

 2 Frame 4 Fixed jaw 6, 8 Movable jaw 10 Screw shaft 12 Tightening screw 16 Bar material 50 Sliding resistance reduction mechanism 54, 56 Piston 60 Ring groove 68 Ball (braking member) 70 Compression spring (biasing member)

Claims (5)

(57) [Claims] 1. A rotary shaft having two oppositely threaded portions spaced apart in the axial direction and erected on a frame so as to be rotatable and axially movable, and axially on both sides of a fixed jaw on the upper surface of the frame. Two movable jaws, spaced apart and screwed into the thread, and a radius that engages the rotating shaft and produces sufficient axial resistance to reduce the maximum sliding resistance acting on the movable jaws. A two-piece vice having a sliding resistance reducing mechanism for elastically applying a directional pressing force to a rotating shaft. 2. The sliding resistance reducing mechanism according to claim 1, further comprising a braking member interposed between the frame and the outer periphery of the rotary shaft so as to be elastically pressed against the outer periphery of the rotary shaft. The vice according to 1. 3. The sliding resistance reducing mechanism is interposed between a plurality of annular grooves formed on the outer periphery of the rotating shaft, the frame, and the outer periphery of the rotating shaft, and any one of the sliding resistance reducing mechanisms is moved along with the axial movement of the rotating shaft. The vice according to claim 1, further comprising a braking member that engages with the annular groove. 4. The vise according to claim 2, wherein said braking member is provided with an urging member for elastically pressing said braking member against the outer periphery of a rotating shaft. 5. A vise according to claim 2, wherein said braking member itself has elasticity.