JP4195270B2 - Shock absorbing mechanism in torque wrench with impact torque generator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a torque wrench provided with an impact torque generating device, and more particularly to an impact absorbing mechanism that absorbs a reaction force when an impact torque is generated.
[0002]
[Prior art]
5 to 6 show a torque wrench provided with a conventional impact torque generating device.
[0003]
This torque wrench 1 shows an example of an electric type, and is a switch unit that is turned on by pulling a trigger handle 15 while using a storage battery V in a dry battery pack 4 detachably attached to a handle portion 11 of a main body as a power source. 16 is a battery-powered electric type that uses an electric motor 20 fed through 16 as a rotational power source. In the rear part of the housing 10, there is an output in the switch unit 16 that outputs an output according to how the trigger handle 15 is pulled. A drive circuit that controls the rotational speed of the electric motor 20 by changing the duty ratio according to the output of the speed control module, and a shut-off circuit block SB that cuts off the electric current to the electric motor 20 when the tightening torque reaches a set value; Is paid.
Reference numeral 17 denotes a forward / reverse selector switch for switching the rotation direction of the electric motor 20, and 18 denotes whether to perform torque control by switching whether to enable or disable the operation of the shut-off circuit block SB. It is a changeover switch for switching.
[0004]
At the front end of the housing 10 are housed a speed reducer 2 that decelerates the rotation of the electric motor 20 and a hydraulic impact torque generator 3 that applies an oil pulse impact to the output shaft 5.
[0005]
The reduction gear 2 includes a sun gear 21 fixed to the output shaft of the electric motor 20, an internal gear 22 fixed to the inner peripheral surface of the motor mount 12 fixed to the housing 10, and the sun gear 21 and the internal gear. The planetary gear 23 includes a plurality of planetary gears 23 that mesh with the carrier 22 and a carrier 24 that supports the planetary gear 23. The carrier 24 supported by the bearings 28 and 28 has a hollow connecting shaft. 25.
[0006]
The hydraulic striking torque generator 3 includes a liner 30 that has a cylindrical shape and an inner surface shape, a jacket 31 that surrounds the outer periphery of the liner 30, end plates 32 and 33 that close both ends of the liner 30, and an output. The shaft 5 includes vanes 50 and 50 attached to a portion surrounded by the liner 30 and hydraulic oil filled in the inner space of the liner 30.
[0007]
The end plate 33 includes a connecting portion that is fitted and connected to the connecting shaft 25 of the carrier 24 of the speed reducer 2, and the liner 30 is rotationally driven by the deceleration output of the prime mover 20.
Then, as with the conventional hydraulic hitting torque generator, when the liner 30 is rotated by the deceleration output of the electric motor 20, the hydraulic hitting torque generating device 3 has the vane 50 and the seal surface of the output shaft 5, and the seal surface of the liner 30. The rotation of the liner 30 is transmitted to the rotary shaft 5 via the hydraulic oil each time.
[0008]
In this case, one of the two chambers located on both sides of the vane 50 is reduced in volume by rotation of the liner 30 and the other is increased in volume, so that the hydraulic fluid in the former chamber becomes high pressure, and the latter chamber The hydraulic oil is low pressure.
Then, the pressure value of the hydraulic oil is detected because the pressure value of the hydraulic oil that has become high corresponds to the tightening torque when the bolt or nut is tightened or loosened on the output shaft 5. By doing so, torque control can be performed.
[0009]
This torque control is performed by adjusting shaft 40 and relief valve 47 arranged in liner 30, piston 60 arranged on end plate 33, rod 61 arranged in hollow connecting shaft 25 in reduction device 2, and outer peripheral surface of connecting shaft 25. And a lever 63 supported by a shaft 65, a lever 66 supported by a shaft 65, a detection switch 19 that is opened and closed by the lever 66, and a shut-off circuit.
In the figure, 62 is a pin for interlocking the rod 61 and the sleeve 63, 64 is a spring urging the sleeve 63, and 67 is a spring urging the lever 66. The sleeve 63 that rotates together with the carrier 24 and the non-rotating lever 66 are configured to maintain a non-contact state during normal operation.
[0010]
The adjustment shaft 40 includes an annular groove 41 communicating with a pair of ports formed on both sides of one of the two sealing surfaces of the liner 30 on the outer peripheral surface, and is connected to one end of the groove 41, and The other end is provided with a through hole 42 reaching the end surface of the adjusting shaft 40, and a relief valve 47 urged by a spring 48 is brought into contact with the end surface of the through hole 42 to close the through hole 42.
The portion where the relief valve 47 is disposed is a room between the end plate 33 and the end surface of the output shaft 5 and the one end surface of the piston 60 exposed through the communication hole 39 formed in the end plate 33. Communicating with
[0011]
As shown in FIG. 7, the shut-off circuit block SB includes a latch circuit L composed of an RS flip-flop, a transistor Q, and a normally closed relay Ry, and the detection switch 19 is connected to the set terminal S in the latch circuit L. Connecting.
The latch circuit L sets the output terminal O to high impedance when the enable terminal E is high and the reset terminal R is low, and sets the output terminal O to low when the enable terminal E is high and the reset terminal R is low. When the enable terminal E and the reset terminal R are at the high level and the set terminal S is at the low level, the output terminal O is at the high level, and when the enable terminal E, the reset terminal R and the set terminal S are at the high level, the output terminal The output level of O is latched in the previous state.
[0012]
Then, when the trigger handle 15 is pulled to turn on the switch unit 16, the electric motor 20 is connected to the battery V of the storage battery pack 4 through the forward / reverse selector switch 17 and the normally closed contact NC in the relay Ry and starts rotating.
At this time, the latch circuit L to which power is turned on simultaneously is initially at a low level because the reset terminal R input is a delay circuit composed of the resistor R and the capacitor C1, but immediately becomes a high level, and the detection switch 19 is off. Since the set terminal S input is at the high level, the output terminal O connected to the base of the transistor Q is at the low level, and the latch terminal is brought into a latch state with the transition of the reset terminal R input to the high level. Hold.
Therefore, the transistor Q is off and the relay Ry is in the normally closed position.
[0013]
When the wrench is operated, the hydraulic oil that has become high pressure tends to flow from the high pressure side to the low pressure side through one port, the groove 41 of the adjusting shaft 40 and the other port. It enters the through hole 42 and presses the relief valve 47. When this pressing force overcomes the urging force of the spring 48, the relief valve 47 opens and hydraulic oil flows to the piston 60 side and presses the piston 60. To do.
As a result, the piston 60 moves the rod 61 backward, and the sleeve 63 that moves backward against the bias of the spring 64 together with the rod 61 rotates the lever 66 to switch the detection switch 19.
When the detection switch 19 is switched, the shutoff circuit block SB cuts off the power supply to the electric motor 20 and holds this cut-off state.
[0014]
The adjustment shaft 40 is screwed into an end plate 32 having one end of the liner 30 closed, and can adjust a relief pressure set by the advance and retreat thereof.
[0015]
When the detection switch 19 is switched on when the tightening torque reaches the set value, the energization to the electric motor 20 is cut off and the electric motor 20 is short-circuited by the well-known method. The braking state is entered, and the rotation stops rapidly.
[0016]
[Patent Document 1]
Japanese Patent Laid-Open No. 6-321381
[Problems to be solved by the invention]
However, in the torque wrench having the conventional hitting torque generating device, when the hitting torque is generated and the rotation is rapidly stopped, the reaction force is transmitted from the planetary gear to the handle portion via the internal gear. It was a burden.
In addition, there are problems such as tendonitis that cause damage to health due to prolonged use.
[0018]
In view of the problems of the torque wrench provided with the conventional hitting torque generating device, the present invention provides a torque wrench provided with the hitting torque generating device in which the hitting torque is generated and the rotation is rapidly stopped. An object of the present invention is to provide an impact absorbing mechanism capable of absorbing force.
[0019]
[Means for Solving the Problems]
To achieve the above object, the shock-absorbing mechanism in the torque wrench with the impact torque generator of the present invention is interposed and the internal gear to the planetary gear meshes with the reduction gear, the clutch mechanism between the gear case, batting In the torque wrench designed to absorb the reaction force when the impact torque is generated by the torque generator by cutting the clutch mechanism, the clutch mechanism is fixed to the casing with the inner peripheral surface formed at a taper angle β. A gear case that has an outer peripheral surface formed at a taper angle β and an inner peripheral surface formed at a taper angle α, and an outer peripheral surface formed at a taper angle α and a gear that meshes the inner peripheral surface with a planetary gear. Conical clutch mechanism that consists of an internal gear and abuts the outer peripheral surface of the internal gear and the inner peripheral surface of the brake shoe by a spring Characterized in that the configuration was.
[0020]
The shock absorbing mechanism in the torque wrench equipped with this striking torque generator cuts the clutch mechanism in which the reaction force generated by the striking torque is interposed between the internal gear that meshes with the planetary gear of the speed reducer and the gear case. To absorb.
[0021]
By configuring the clutch mechanism with a conical clutch mechanism, the clutch mechanism can be incorporated even with a small torque wrench with limited space.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an impact absorbing mechanism in a torque wrench provided with an impact torque generating device of the present invention will be described below with reference to the drawings.
[0023]
1 to 3 show an embodiment of an impact absorbing mechanism in a torque wrench provided with a striking torque generator according to the present invention.
[0024]
The torque wrench 79 provided with this shock absorbing mechanism is for tightening bolts and nuts by the same mechanism as in the conventional example. The torque is generated by the hydraulic striking torque generator 3 as in the prior art, and the tightening torque is set. When this value is reached, an impact torque is generated and its rotation is rapidly stopped.
[0025]
As shown in FIG. 3, the shock absorbing mechanism 80 of the present invention has an inner peripheral surface formed at a taper angle β, a gear case 81 fixedly attached to the casing 10, and an outer peripheral surface formed at a taper angle β. The main components are a brake shoe 82 whose surface is formed at a taper angle α and an internal gear 83 whose outer peripheral surface is formed at a taper angle α and whose inner peripheral surface is engaged with the planetary gear 23.
[0026]
A bearing insertion hole 88 is formed in the motor mounting base 86 having a bearing insertion hole 88 formed in the center of the shaft center. The bearing insertion hole 88 is inserted into the center of the shaft center. A plurality of spring insertion holes 87 are formed on the outer periphery, the spring 85 inserted into the spring insertion hole 87 is brought into contact with the spring receiving surface 84a of the thrust plate 84, and the internal force is received by the gear contact surface 84b of the thrust plate 84. A conical clutch mechanism that abuts the outer peripheral surface of the gear 83 and the inner peripheral surface of the brake shoe 82 is employed.
[0027]
In this case, the setting of the slip torque generated by the contact between the outer peripheral surface of the internal gear 83 and the inner peripheral surface of the brake shoe 82 is such that the number of springs 85 inserted into the spring insertion holes 87 formed in the motor mounting base 86 is increased or decreased. Adjustment is made by changing the spring constant of the spring 85.
The outer surface of the brake shoe 82 is configured with the same inclination angle β as the inner peripheral surface of the gear case 81, and is press-fitted and fixed to the gear case 81 so as not to rotate due to the rotational force of the internal gear 83.
[0028]
In the above configuration, the reaction force from the side on which the bolt or nut received by the tightening tool of the bolt or nut attached to the tip of the output shaft 5 due to the generation of the impact torque is the output shaft 5 or the sun gear. 21, it is transmitted to the internal gear 83 via the planetary gear 23, but the outer peripheral surface of the internal gear 83 is in contact with the inner peripheral surface of the brake shoe 82 by the slip torque adjusted by the spring 85. When the clutch mechanism is disengaged, that is, the outer peripheral surface of the internal gear 83 and the inner peripheral surface of the brake shoe 82 are disconnected, the handle exceeds the gear case 81 fixedly attached to the casing 10. It is possible to prevent transmission to the part 11.
[0029]
Next, FIG. 4 shows a reference example of an impact absorbing mechanism in a torque wrench provided with an impact torque generating device.
The shock absorbing mechanism 90 includes a gear case 91 fixedly attached to the casing 10 and an internal gear 93 sandwiched by two brake discs 92a and 92b of a hollow disk as main components. A flat clutch mechanism that presses the side surface of one of the brake shoes 92b with a spring 85 inserted into the spring insertion hole 87 formed on the inner side and adjusts the slip torque generated by the both side surfaces of the internal gear 93 and the side surfaces of the brake shoes 92a and 92b It is a thing.
[0030]
Also in the case of this reference example, as in the case of the conical clutch mechanism of the above embodiment , the reaction force when the impact torque is generated exceeds the gear case 81 fixedly attached to the casing 10 when the clutch mechanism is broken, and the handle It is possible to prevent transmission to the part 11.
[0031]
As described above, the shock absorbing mechanism in the torque wrench provided with the impact torque generating device of the present invention has been described based on the embodiments thereof, but the present invention is not limited to the configurations described in the above embodiments, and the purpose thereof The configuration can be changed as appropriate without departing from the scope of the invention.
[0032]
【The invention's effect】
As described above, according to the present invention, in a torque wrench equipped with a striking torque generating device, the reaction force generated by the generation of the striking torque is absorbed by the clutch mechanism as the shock absorbing mechanism, and the operator's burden caused by the reaction force is absorbed. It is possible to provide a torque wrench that is reduced and does not cause health damage such as tendonitis even when used for a long time .
By configuring the clutch mechanism with a conical clutch mechanism, the clutch mechanism can be incorporated even with a small torque wrench with limited space.
[Brief description of the drawings]
FIG. 1 is an overall view of a partial cross section showing an embodiment of a torque wrench provided with an impact absorbing mechanism of the present invention.
FIG. 2 is an enlarged partial cross-sectional view illustrating the shock absorbing mechanism.
FIG. 3 is an exploded view for explaining the shock absorbing mechanism.
4 is a partial enlarged sectional view illustrating a shock absorbing mechanism showing a reference example of a torque wrench having a shock absorbing mechanism.
FIG. 5 is an overall view showing a conventional torque wrench.
FIG. 6 is a partial cross-sectional view for explaining the operation of a conventional torque wrench.
FIG. 7 is a circuit diagram of a conventional torque wrench.
[Explanation of symbols]
2 Reduction gear 3 Impact torque generator 23 Planetary gear 79 Torque wrench 80 Shock absorbing mechanism 83 Internal gear 93 Internal gear

Claims (1)

A clutch mechanism is interposed between the internal gear that meshes with the planetary gear of the reduction gear and the gear case, and the reaction force when the impact torque is generated by the impact torque generator is absorbed by turning the clutch mechanism off . In a torque wrench, the clutch mechanism includes a gear case having an inner peripheral surface formed at a taper angle β and fixedly attached to a casing, an outer peripheral surface formed at a taper angle β, and an inner peripheral surface formed at a taper angle α. And an internal gear having an outer peripheral surface formed at a taper angle α and an inner peripheral surface formed with a gear meshing with the planetary gear, and the outer peripheral surface of the internal gear and the inner peripheral surface of the brake shoe by a spring. An impact absorbing mechanism in a torque wrench provided with a striking torque generating device, characterized in that it is composed of a conical clutch mechanism that abuts on the outer side.

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