JPH0825233A - Ratchet wrench - Google Patents

Abstract

PURPOSE:To provide a ratchet wrench facilitating the extracting and fastening work of a nut from a tie bar and capable of saving the work. CONSTITUTION:This ratchet wrench is provided with a wrench main body 21 provided on the inner periphery of a circular section coupled with the outer periphery of a nut 24, storing ratchet claws 25, and uniformly distributed with box-like notch sections different in number from the grooves 24a of a nut 24 and formed into inner cylindrical shapes on one side; a claw pin 26 fitted to the wrench main body 21; the ratchet claws 25 loosely coupled with the claw pin 26; and stopper pins 28 planted on the ratchet claws 25. Each ratchet claw 25 is formed with a spring 27 excited protrusively in the center direction of the wrench main body 21 and a ratchet section cover 29 having an oblong hole 29a limiting the shift quantity of the ratchet claw 25 via the stopper pin 28. The fastening force of the nut 24 is borne by the ratchet claws 25 and the contact faces between the cylinder section of the ratchet claws 25 and the inside cylinder sections of the claw storage hole of the wrench main body 21, and a large fastening torque can be borne.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dedicated large ratchet wrench for tightening or removing a large cylindrical nut having a U-shaped groove such as a tie bar in a mold clamping device such as an injection molding machine.

[0002]

2. Description of the Related Art In a conventional mold clamping mechanism of an injection molding machine, when a mold 1 is replaced, one upper tie bar 3'is molded as shown in FIGS. 10 and 11 (Japanese Utility Model Publication No. 50-23656). The method of pulling out from the board 2 and facilitating the replacement work of the mold 1 is adopted. At this time, the nut 4 at the end of the tie bar 3'is removed and the tie bar 3'is returned to its original position after the mold replacement. It is put back and tightened. Conventionally, the rotational tightening of the grooved cylindrical tightening nut of the tie bar of the mold clamping mechanism of the injection molding machine, the press machine or the like has been conventionally performed with reference to FIG.
In order to avoid the arm of the wrench 10 from hitting the surrounding members, an appropriate angle (the groove on the outer circumference of the nut is 6) is used. It is usual that the wrench 10 is pulled out from the nut 4 by turning it about 30 degrees), the surface of the wrench 10 is returned, and the wrench 10 is fitted and tightened.

However, when the tie bar 3 has a large male screw diameter of 200 mm or more, the weight of the wrench 10 becomes large and the tightening torque also becomes large. Therefore, the wrench 10 is pushed by using the pushing / pulling force of the hydraulic cylinder or the crane. Since it is necessary to rotate the arm of the wrench, the work of replacing the wrench 10 is a large-scale operation and takes a lot of work time. Further, in order to omit the replacement of the wrench, it is conceivable to adopt a ratchet wrench mechanism having a conventional structure, but the conventional one is as shown in FIGS. 13 to 15 (JP-A-48-104196). This is a method of supporting the load of the tightening torque by the pin 5 and the ratchet pawl 6, and cannot endure the tightening of the large-sized nut as described above in terms of structure and strength. Further, in such a ratchet wrench having a structure in which a nut is tightened via the gear 11, the outer diameter of the tightening portion of the ratchet wrench becomes too large with respect to the outer diameter of the nut, and it may not be used in a narrow place.

[0004]

As described above, the large wrench used for the large tightening nut of the tie bar of the conventional injection molding machine is heavy and has a large tightening torque, and a hydraulic cylinder, a crane or the like is used for the tightening work. It is necessary to frequently remove the wrench from the nut and replace it to tighten the arm by using the auxiliary tool of wrench to avoid hitting the surrounding member with the arm of the wrench. However, there is a drawback that it takes a lot of work time. Further, in the conventional ratchet wrench structure, the strength of the ratchet pawl support portion is insufficient, and the outer diameter of the wrench becomes large and heavy, which makes it difficult to use in a narrow space. The present invention has been proposed in order to solve the above-mentioned conventional problems, and it is an object of the present invention to provide a ratchet wrench that can easily remove and tighten a nut from a diver and can save the work. Is.

[0005]

Therefore, according to the present invention, a ratchet for tightening a cylindrical nut having a plurality of U-shaped grooves parallel to the axis on its outer periphery by directly engaging the ratchet pawls with the grooves of the nut. In the wrench, a box-shaped notch that is a hole for accommodating the ratchet pawl that is provided on the inner circumference of the annular portion that engages with the outer circumference of the nut, and one side has an inner cylindrical shape A wrench body that is distributed and provided, a claw pin attached to the shaft center of the inner cylindrical portion of the cutout portion of the wrench body, and a cylindrical shape whose rotation side has the same radius as the inner cylindrical shape of the cutout portion of the wrench body. The ratchet pawl that is loosely fitted to the pawl pin, the stopper pin implanted in the ratchet pawl, the spring biased to push the ratchet pawl toward the center of the wrench body, and the wrench body A ratchet part cover fixed to the surface and having a long hole for limiting the amount of movement of the ratchet claw via the stopper pin, and tightening the nut with a ratchet claw, a cylindrical part of the ratchet claw, and a wrench. It is constructed so as to bear a large tightening torque by being supported by the contact surface of the claw housing hole of the main body with the inner cylindrical portion, and this is a means for solving the problem.

According to the present invention, instead of the ratchet cover fixed to the side surface of the annular portion that engages with the nut of the wrench body, the ratchet cover is rotatable concentrically with the annular portion and the stopper pin is provided. There are a cam hole with a cam shape that can change the range of movement of the stopper pin depending on the turning position, and a rotating cam that has the same number of ratchet pawls and a long hole that is opened in the circumferential direction of the rotating cam. A guide pin that guides the rotary cam so that the rotary cam can rotate while being in contact with the annular portion of the wrench body, and holding the ratchet pawl by pulling the ratchet pawl into the notch depending on the rotational position of the rotary cam; The operation can be switched, and this is a means for solving the problem.

Further, according to the present invention, a cylindrical nut having a plurality of U-shaped grooves parallel to the axis line on the outer periphery is engaged with the nut in a ratchet wrench in which a ratchet pawl is directly engaged with the groove of the nut. The box-shaped cutouts that are evenly arranged on the inner circumference of the annular part of the wrench body, and the cutouts that are symmetrically arranged alternately with the cutouts and on the circumference. Part (hereinafter, referred to as a sub-notch part), a notch part of the wrench body and a claw pin implanted in an axial center of an inner cylindrical part of the sub-notch part, and a rotation side of the notch part and the sub-notch part. A ratchet pawl that is loosely fitted to the pawl pin in a cylindrical shape having the same radius as the inner cylinder, and a sub ratchet pawl symmetrical to the ratchet pawl, and a stopper pin implanted in the ratchet pawl and the sub ratchet pawl, and Ratchet claw and vice The ratchet pawl can be rotated concentrically with the spring urged to push the chette pawl toward the center of the wrench body and the annular portion of the wrench body, and the movement range of the ratchet pawl can be changed by the rotation position via the stopper pin. A rotary cam with a cam-shaped cam hole and a cam hole for the auxiliary ratchet pawl that is symmetrical with the cam hole alternately arranged in the same number as the ratchet pawl, and a long hole bored in the circumferential direction of the rotary cam. Via a guide pin that guides the rotary cam so that it can rotate while being in contact with the annular portion of the wrench body, and can withstand a large tightening torque of the nut while cutting all ratchet pawls by the rotational position of the operation plate. It is possible to switch between holding by pulling into the notch, ratchet pawl operation, and sub ratchet pawl operation.
The configuration is such that the tightening rotation direction of the nut can be changed with the wrench set, and this serves as a means for solving the problem.

[0008]

The present invention is a ratchet wrench having a structure in which a ratchet pawl directly engages with the groove of the nut when tightening a cylindrical nut with a U-shaped groove, and the ratchet pawl is loosely fitted with a gap provided by a pawl pin. Since the nut tightening force is not directly applied to the claw pin, the nut tightening force is the same as the ratchet claw and the cylindrical part of the ratchet claw and the inner cylindrical part of the ratchet claw housing cutout hole of the wrench body. It is received at the contact surface of the and transmitted to the ratchet wrench body, and can withstand a large torque sufficiently. Further, when the nut is tightened, the ratchet pawl and the spring are effective by reciprocating a relatively small angle (about 30 degrees) so that the nut can be tightened in one direction. Also, in the case where the moving range of the ratchet pawl can be changed by the rotating cam, it is possible to switch between holding by pulling into the notch of the ratchet pawl via the cam and stopper pin depending on the rotational position of the rotating cam, and ratchet pawl operation. Therefore, when engaging the ratchet wrench with the nut, it is possible to save the number of steps of pressing and holding the etchet tab. In addition to symmetrical ratchet pawls on the circumference and a rotating cam that can change the range of movement of the ratchet pawl, the ratchet pawl operation and the sub ratchet pawl are all operated by the rotational position of the rotary cam in addition to the above-mentioned action. Holding by pulling into the notch, one-way tightening rotation (or withdrawal rotation) by ratchet pawl operation, and three-way withdrawal rotation (or tightening rotation) in the opposite direction by the operation of the sub-ratchet pawl are switched. The ratchet wrench is easy to set, and the nut rotation direction can be freely changed with the ratchet wrench set.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments of the drawings. FIGS. 1 to 9 show the embodiments of the present invention. First, FIG. 1 is a front view of a ratchet wrench of the first embodiment, and FIG. 2 is A of FIG.
FIG. 3 is a sectional view taken along the line BB of FIG. 1 to 3
In the figure, 23 is a tie bar that connects the mold plate of an injection molding machine (not shown), and 24 is a cylindrical nut that has a plurality of U-shaped grooves parallel to the axis on the outer circumference. 20 is nut 2
It is a first ratchet wrench for directly engaging and tightening the toe 25a of the ratchet pawl 25 in the groove 24a of No. 4. This first
On the inner circumference of the annular portion of the wrench body 21 having the long arm 21a, which is the main body of the ratchet wrench 20, there is a box-shaped notch 21b for accommodating the ratchet pawl 25, which differs from the number of grooves of the nut 24 (six in FIG. 1). The quantity (4 in Fig. 1) is evenly distributed on the circumference. One side of the cutout portion 21b has an inner cylindrical shape.

Each notch 21 is formed on both sides of the wrench body 21.
The ratchet part cover 29 is fixed by bolts for each b, and the claw pins 26 are supported by the covers 29 on both sides. The pawl pin 26 is attached to the shaft center of the inner cylindrical portion of the cutout portion 21b, and the ratchet pawl 25 is attached to the pawl pin 26.
Are loosely fitted with a gap. The rotation side of the ratchet pawl 25 is formed into a cylindrical strip 25a having the same radius as the inner cylindrical shape 21c of the cutout portion 21b of the wrench body 21, and the pawl pin 26 forms the inner cylindrical shape 21c of the cutout portion and the cylinder of the ratchet pawl. It is supported so as to be in contact with the strip 25a. A stopper pin 28 is embedded in the ratchet pawl 25.
Reference numeral 27 is a spring urged to push the ratchet pawl 25 toward the center of the wrench body 21. Further, a long hole 29a is formed in the ratchet part cover 29 on one side, and this restricts the movement amount of the ratchet pawl 25 via the stopper pin 28 so that the ratchet pawl 25 does not come out too much.

Next, the operation of the first ratchet wrench 20 will be described. The first ratchet wrench 20 has a groove 2 of the nut when the cylindrical nut 24 having a U-shaped groove is tightened.
The ratchet toe 25b is directly engaged with 4a. Further, since the ratchet claw 25 is loosely fitted to the claw pin 26 with a gap, the nut tightening force is not applied to the claw pin 26, and the nut tightening force is the ratchet claw 25.
Since it is adapted to be received by the contact surface between the cylindrical portion 25a of the ratchet pawl and the inner cylindrical portion 21c of the cutout portion 21b of the wrench main body 21 and transmitted to the ratchet wrench main body 21, it can withstand a large torque sufficiently. It has a structure. Further, since the number of grooves of the nut 24 is 6 and the number of ratchet pawls 25 is 4, when the nut 24 is tightened, if the ratchet pawl 25 and the spring 27 are operated repeatedly by a reciprocating stroke slightly exceeding 30 degrees, the ratchet action is caused by the ratchet action. The nut can be rotated and tightened.

Next, FIGS. 4 to 6 show a second embodiment of the ratchet wrench according to the present invention. In this embodiment, the ratchet pawl can be held in a retracted state by rotating a rotary cam. 4 is a front view of the second ratchet wrench 30, FIG. 5 is a side view including the C-C cross section of FIG. 4, and FIG. 6 is a D-D cross section of FIG. Now the second ratchet wrench 3
0 will be described. The cutout portion 3 of the wrench body 31
The shape and position of 1b are the same as those of the first ratchet wrench 20. The ratchet pawl 25 and the spring 27 are also the same. Explaining a part different from the first ratchet wrench 20 here, instead of the ratchet part cover fixedly mounted on the side surface of the annular part of the wrench body 31 that engages with the nut, it is concentric with the annular part of the wrench body 31. The ring portion 35b of the rotary cam 35 is fitted into the cylindrical portion 31c provided on the edge of the annular portion of the wrench body 31 so as to be rotatable, and the ring surface of the rotary cam 35 is extended in the circumferential direction. 4 holes 35d equally
The rotary cam 35 is opened in the annular part of the wrench body 31.
Guide pins 3 for guiding the rotary cam 35 so that the rotary cam 35 can be rotationally moved while being in contact with the annular portion of the wrench body 31.
7 are evenly arranged. Further, the stopper pin 28 of the ratchet pawl 25 is inserted into the rotary cam 35, and cam holes 35a for limiting the movement range of the stopper pin 28 are provided in the same number as the ratchet pawl depending on the rotating position. A turning operation lever 35c is provided.

Next, the operation of the second ratchet wrench 30 will be described. The tightening and rotating function of the second ratchet wrench 30 around the ratchet claw is the same as that of the first ratchet wrench 20. However, the rotary cam 35 is provided and held by pulling the ratchet pawl 25 into the notch 31b through the cam hole 35a and the stopper pin 28 depending on the rotational position of the rotary cam 35 (the position shown in the right half of FIG. 4).
And the operation of the ratchet pawl 25 (the position shown in the left half of FIG. 4 and the position of the operating lever 35c 'shown by the two-dot chain line) can be switched, so that when the second ratchet wrench 30 is engaged with the nut. , It is not necessary to hold the ratchet claw 25 and place it.

Next, FIGS. 7 to 9 show a third embodiment of the ratchet wrench of the present invention. In this embodiment, symmetrical ratchet pawls are provided alternately, and the direction of tightening rotation is changed by rotating the rotary cam. And the ratchet pawl can be held in the retracted position.
FIG. 8 is a side sectional view of the ratchet wrench 40, and FIG. 9 is a sectional view taken along line F-F in FIG. In the third ratchet wrench 40, the shape and position of the cutout portion 41b of the wrench body 41 are the same as those of the first ratchet wrench 20, and at the same time, the sub cutout portion 41b 'having a shape symmetrical to these is provided. Are provided between the notches 41b. The ratchet pawl 25 and the spring 27 are the same as those in the above-described embodiment, but the sub ratchet pawl 25 'housed in the sub cutout portion 41b' has a symmetrical shape with the ratchet pawl 25. As shown in FIG. 7, the notch portion 41b and the sub-notch portion 41b 'have one side surface integrated with the wrench body 41 as shown in FIG. 9, and the claw pin 36 is fixed to the side surface of the wrench body 41. To be done.

The rotating cam 45 of the third ratchet wrench 40 is, like the second ratchet wrench 30, rotatable on the side surface of the annular portion that engages with the nut of the wrench body 41, concentrically with the annular portion. As described above, the seal portion 45b of the rotary cam 45 is fitted to the cylindrical portion 41c provided on the edge of the annular portion of the wrench body 41, and the circular holes of the rotary cam 45 are equally divided into the elongated holes 45d in the circumferential direction. 4 pieces are opened in the wrench body 4
Four guide pins 37 for guiding the rotating cam 45 are provided so as to be equally arranged so that the rotating cam 45 can rotate while being in contact with the one annular portion. Further, the stopper pin 28 of the ratchet pawl 25 and the auxiliary ratchet pawl 25 'pawl is inserted in the rotating cam 45, and the cam hole 45a and the cam hole 45a having a cam shape capable of changing the moving range of the stopper pin 28 depending on the rotating position of the rotating cam 45. 45a 'is the ratchet pawl 25
And the sub ratchet pawls 25 'are provided in the same number.

At the positions of the cam holes 45a and 45a ', the stopper pin 28 of the ratchet pawl 25 is placed in the cam hole 45a.
When the ratchet pawl 25 is engaged with the nut in the widened portion of a, the stopper pin 28 of the auxiliary ratchet pawl 25 'is located at the narrow lock position of the cam hole 45a' (left half of FIG. 7). Position shown in Fig. 2), sub ratchet pawl 2
When the stopper pin 28 of 5'is in the widened portion of the cam hole 45a 'and the sub ratchet pawl 25' engages with the nut, the stopper pin 28 of the ratchet pawl 25 will lock the cam hole 45a in a narrow lock. The ratchet pawls 25 and the auxiliary ratchet pawls 25 ′ in the intermediate position are located at the cutout portion 41 of the wrench body 41.
When it is retracted into the b and the sub cutout portion 41b ', it is in a locked state (the position shown in the right half of FIG. 7). An arm 45c is provided on the rotary cam 45, and an operating lever 46 is rotatably attached via a pin 48 to a support 49 fixed to the arm 45c as shown in FIG. 47 causes the arm of the operating lever 46 to move to the arm 4
The claw 46a at the lower end of the actuating lever 46 is urged in the opening direction with respect to 5c and engages with the groove 41d formed on the outer periphery of the annular portion of the wrench body to position and prevent the rotation cam 45 from rotating. .

The operation of the third ratchet wrench 40 will now be described. The tightening and rotating function of the third ratchet wrench 40 around the ratchet pawl is the same as that of the first ratchet wrench 20, but the ratchet pawl 25 and the ratchet pawl 25 are symmetrical to this. Since the auxiliary ratchet pawls 25 'are provided on the circumference in a staggered manner, the ratchet pawl 25 and the auxiliary ratchet pawl 25' in the notches 41b and 41b 'can be adjusted by the rotational position of the rotary cam 45 in addition to the above-mentioned operation. Holding by pulling in, switching in one direction by operation of ratchet pawl 25 (or withdrawal rotation) and withdrawal rotation in the opposite direction by operation of sub ratchet pawl 25 '(or tightening rotation). It is possible to set the 3rd ratchet wrench 40 easily, and freely rotate the nut while it is set. And it has a structure that is in place.
Further, the rotary cam 45 can be stopped and held at the above-mentioned three switching positions by the pawl 46a at the lower end of the operating lever 46.

[0018]

As described in detail above, if the ratchet wrench of the present invention is used for a large tightening nut of a tie bar of a conventional injection molding machine, the tightening torque is large, and an assist of a hydraulic cylinder, a crane or the like is provided for tightening work. Even if the rotation angle of the arm is limited, you do not need to pull out the wrench from the nut and replace it in order to rotate the arm using the tool and avoid hitting the arm around the wrench.
The work of removing and tightening the nut from the tie bar is easy, and work time can be saved. In addition, since the ratchet pawl of the wrench has a structure that directly engages with the outer peripheral groove of the nut, it is much more compact than the structure of the conventional ratchet wrench, and even for large torque when tightening and withdrawing, Since the force received by the ratchet pawl in the circumferential direction is supported by the contact surface between the cylindrical surface of the ratchet pawl and the inner cylindrical surface of the wrench body, the strength of the ratchet pawl support portion can be sufficiently maintained.

[Brief description of drawings]

FIG. 1 is a front view of a ratchet wrench according to a first embodiment of the present invention.

FIG. 2 is a view on arrow A in FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a front view of a ratchet wrench according to a second embodiment of the present invention.

5 is a sectional side view of a part of FIG.

FIG. 6 is a sectional view taken along line D-D in FIG. 4.

FIG. 7 is a front view of a ratchet wrench according to a third embodiment of the present invention.

FIG. 8 is a side sectional view of FIG.

9 is a sectional view taken along line F-F in FIG. 7.

FIG. 10 is a side view showing a conventional working state in which a mold is replaced from a mold plate of an injection molding machine.

11 is a front view of FIG.

FIG. 12 is a front view showing an example of a conventional wrench.

FIG. 13 is a side view showing a conventional ratchet wrench.

FIG. 14 is a partial front view showing an engaged state of a conventional ratchet wrench.

FIG. 15 is a front partial view showing a state of a pawl in a conventional ratchet wrench in a free rotation direction.

[Explanation of symbols]

 20 1st ratchet wrench 21 Wrench body 21b Notch 23 Tie bar 24 Groove nut 25 Ratchet claw 26 Pin 27 Spring 28 Stopper pin 29a Long hole 30 Second ratchet wrench 31 Wrench body 31b Notch 35 Rotating cam 35a Cam 37 Guide pin 40 Third ratchet wrench 41 Wrench body 41b Cutout 41b 'Sub cutout 45 Rotating cam 45a, 45a' Cam

Claims (3)

[Claims] 1. A ratchet wrench in which a ratchet claw is directly engaged with a groove of a cylindrical nut having a plurality of U-shaped grooves parallel to an axis on the outer periphery to tighten the annular nut. The same as the wrench body provided with the ratchet pawl storage hole provided on the inner circumference of the part, in which a box-shaped notch part of which one side has an inner cylindrical shape is provided by allocating a number different from the number of grooves of the nut. The claw pin attached to the shaft core of the inner cylindrical portion of the cutout portion of the wrench body, and the rotation side is loosely fitted to the claw pin with a cylindrical shape having the same radius as the inner cylindrical shape of the cutout portion of the wrench body. A ratchet pawl that is present, and a stopper pin that is implanted in the ratchet pawl,
A ratchet part cover having a long hole for limiting the amount of movement of the ratchet pawl via a spring biased to push the ratchet pawl toward the center of the wrench body and the stopper pin fixed to the side surface of the wrench body. The nut tightening force is supported by the ratchet pawl, the contact surface between the ratchet pawl cylindrical part and the inner cylindrical part of the claw housing hole of the wrench body to withstand a large tightening torque. Ratchet wrench characterized by doing. 2. The ratchet wrench according to claim 1, wherein the ratchet wrench body is rotatable in concentric with the annular portion instead of the ratchet portion cover fixed to the side surface of the annular portion that engages with the nut of the wrench body. The rotation pin is provided with the same number of cam holes as the ratchet pawls, and a cam hole having a cam shape capable of changing the movement range of the stopper pin depending on the turning position. By providing a guide pin that guides the rotary cam so as to be able to rotate while contacting the annular portion of the wrench body through the opened long hole, and by drawing the ratchet pawl into the notch depending on the rotational position of the rotary cam. A ratchet wrench characterized by being able to switch between holding and actuation of the ratchet pawl. 3. A ratchet wrench that engages with a nut in a ratchet wrench in which a ratchet claw is directly engaged with a groove of a cylindrical nut having a plurality of U-shaped grooves parallel to the axis on the outer periphery. Box-shaped cutouts provided equally on the inner circumference of the annular part of, and the cutouts symmetrically provided with the cutouts and the cutouts provided alternately on the circumference. A sub-notch part), a claw pin embedded in the shaft center of the inner cylinder part of the notch part and the sub-notch part of the wrench body, and the inner cylinder of the notch part and the sub-notch part on the rotation side. Ratchet pawl with a cylindrical shape having the same radius as that of the ratchet pawl that is loosely fitted to the pawl pin and a sub ratchet pawl symmetrical to the ratchet pawl, a stopper pin implanted in the ratchet pawl and the sub ratchet pawl, and the ratchet pawl and Deputy ratchet claw A spring that is biased to push out toward the center of the wrench body and a cam shape that can rotate concentrically with the annular portion of the wrench body and that can change the range of movement of the ratchet pawls by the rotation position via the stopper pin. With the cam hole and the cam hole for the auxiliary ratchet pawl that is symmetrical to the cam hole and the same number as the ratchet pawl, the rotary cam is opened, and the long hole bored in the circumferential direction of the rotary cam is used. It consists of a guide pin that guides the rotating cam so that it can rotate while keeping contact with the annular part of the wrench body. It is possible to switch between three ways: holding by pulling, ratchet pawl operation, and sub ratchet pawl operation. With the wrench set, the nut tightening rotation direction can be changed. Ratchet wrench characterized by being configured to Erareru so.