WO2005099965A1

WO2005099965A1 - Pulse wrench

Info

Publication number: WO2005099965A1
Application number: PCT/JP2004/005043
Authority: WO
Inventors: Masato Oka
Original assignee: Nippon Pneumatic Manufacturing Co., Ltd.
Priority date: 2004-04-07
Filing date: 2004-04-07
Publication date: 2005-10-27

Abstract

In a pulse wrench having a percussion pulse generating mechanism, it is intended to facilitate the processing of an oil passage which establishes communication between high and lower pressure chambers in one percussion pulse generating state which is established twice during one revolution of a cylinder. To this end, the invention establishes twice in one revolution of a cylinder (11) a percussion pulse generating state in which a high pressure chamber (H) and a low pressure chamber (L) are formed in a cylinder chamber (21) during one revolution of the cylinder by rotation of the cylinder (11) relative to an anvil (23), wherein in one percussion pulse generating state, communication between the high and low pressure chambers (H, L) is established by the oil passage so as to allow the operating oil in the high pressure chamber (H) to flow into the low pressure chamber (L), thereby eliminating the generation of percussion pulses. The oil passage is composed of two arcuate holes (32, 33) of different peripheral lengths formed in the rear cover (15) of the cylinder (11), four communication oil holes (34) communicating with the opposite ends of each of the arcuate holes (32, 33), and a communication passage (35) formed in the rotor (23a) of the anvil (23).

Description

Specification

Pulse wrench Technical field

The present invention relates to a pulse wrench having a hydraulic striking pulse generating mechanism. Background art

As a pulse wrench of this type, a pulse wrench described in Japanese Utility Model Application Laid-Open Publication No. Hei 12-1990 (Patent Document 1) is conventionally known. This pulse wrench comprises an air motor driven by compressed air, and a hydraulic striking pulse generating mechanism connected to a rotor of the air motor.

The striking pulse generation mechanism connects a cylinder to the mouth of the air motor, and connects two opposing blades to the rotor by a rotor located in the cylinder of the anvil that passes through the front cover of the cylinder. The blade is movably supported in the radial direction, and each blade is urged toward the inner periphery of the cylinder by an elastic body. When the cylinder rotates relative to the anvil, the cylinder rotates every time the cylinder rotates 180 °. A high-pressure chamber and two low-pressure chambers are formed inside the cylinder, and a single impact pulse is generated from two impact pulse generation states formed during one rotation of the cylinder. In the generation state, the high-pressure chamber and the low-pressure chamber are communicated with each other so that the hydraulic oil in the high-pressure chamber flows to the low-pressure chamber so that no impact pulse is generated. Loose is generated to apply a rotational impact to the anvil.

By the way, in the pulse wrench described in Patent Document 1, when a striking pulse is generated, the two high-pressure chambers formed at diagonal positions have different volumes. There is a problem that the power is different and the rotation balance of the ampill is poor. In order to solve such a problem, Japanese Utility Model Publication No. JP-A-Heisei 6-000113 (Patent Document 2) discloses that two high pressures formed inside a cylinder when the cylinder rotates relative to an anvil. A pulse wrench has been proposed in which the chamber volumes are made equal. Disclosure of the invention

By the way, in the pulse wrench described in Patent Literature 2, one impact pulse is generated from among the impact pulse generation states formed twice by one rotation of the cylinder with respect to the anvil. The high-pressure chamber and the low-pressure chamber are communicated with each other through an oil passage in a raw state, so that the oil in the high-pressure chamber flows to the low-pressure chamber.構成 Because it is a structure that processes many parts such as lid anvils and blades, there is an inconvenience that processing is troublesome.

In particular, since the oil passage formed in the blade is formed by drilling from the small end face facing the inner lid, it is not possible to machine a hole with a large inside diameter. There is a disadvantage that it takes time.

In addition, the oil passage has a complicated shape, a long overall length, and a thin-walled blade. Therefore, the cross-sectional area of the flow passage is small, and the resistance when hydraulic oil flows through the oil passage is large. As a result, hydraulic oil does not flow smoothly from the high-pressure chamber to the low-pressure chamber, creating a pressure difference between the high-pressure chamber and the low-pressure chamber, and this pressure difference becomes the rotational resistance of the cylinder. There is also the disadvantage that they cannot be formed and the impact pulse becomes uneven.

Furthermore, since the oil passage formed in the blade opens 1 = 1 at the end face with a small blade width, the seal width of the contact surface where the inner lid of the cylinder and the end face of the blade come into contact is reduced, and the above-mentioned contact The oil in the high-pressure chamber easily leaks to the low-pressure chamber side on the surface, and there is a problem in the sealing performance. Also, since the oil passage formed in the blade is formed at one end on the inner lid side, when the blade is installed, if one end and the other end are reversed, a hydraulic impact pulse is generated. However, there is a disadvantage that it takes time to assemble the pulse wrench, since the blade has a directivity in assembling the blade.

An object of the present invention is to provide a pulse wrench having a hydraulic striking pulse generating mechanism, to facilitate processing of an oil passage connecting a high pressure chamber and a low pressure chamber and to reduce flow resistance of hydraulic oil. The purpose is to improve the sealing performance at the end face of the blade, and to facilitate the assembly of the pulse wrench.

In order to solve the above-mentioned problems, in the present invention, a hydraulic striking pulse generating mechanism is connected to a port rotated by compressed air, and the striking pulse generating mechanism has a front and rear cover, Thereafter, a cylinder having a cover connected to the rotor, a front end protruding from the front cover, a rear end supported by the rear cover, and a central portion formed by a rotor portion located inside the cylinder, Two blades that are inserted into the blade holes formed in the rotor and are movable in the radial direction of the rotor, and an elastic body that urges each blade toward the inner peripheral surface of the cylinder The cylinder has two equal-volume high-pressure chambers and two equal-volume low-pressure chambers inside the cylinder each time the cylinder rotates 180 ° with respect to the anvil. In a pulse wrench in which the hydraulic oil in the high-pressure chamber flows from the oil passage to the low-pressure chamber every rotation of the damper, the oil passage is formed in a circumferential direction formed at a position facing the circumference of the rear cover. A pair of arc holes having different lengths, four oil passage holes communicating from the inner surface of the rear cover to both ends of each arc hole, and an oil passage hole at an end facing the rear cover of the anvil. Consists of four communication passages provided at opposing positions, one of two oil passages communicating with both ends of each arc-shaped hole for each rotation of the cylinder with respect to the anvil. The system was designed so that it could communicate with the user.

Here, the rear cover is formed by a first cover and a second cover which are abutted with each other, and a pair of arc-shaped holes are formed on one of the abutting surfaces of the first cover and the second cover, If an oil passage is formed in the first cover on the cylinder side, the oil passage can be processed more easily.

Since the present invention is configured as described above, the following effects can be obtained.

i) A high-pressure chamber and a low-pressure chamber are formed during one revolution of the cylinder. Among the two impact pulse generation states, in one impact pulse generation state, each of the four oil passage holes provided in the cylinder cover This coincides with the communication passage formed in the rotor portion to form an oil passage, and the high-pressure chamber and the low-pressure chamber communicate with each other through the oil passage, so that the hydraulic oil in the high-pressure chamber can flow into the low-pressure chamber. A single, large hydraulic pulse can be applied to the anvil in one cylinder revolution. ii) Since the oil passage that connects the high-pressure chamber and the low-pressure chamber has a simple configuration consisting of an arc-shaped hole and an oil passage hole provided in the rear cover, and a communication passage formed in the rotor, the oil passage is machined. Is easy.

iii) Since an oil passage is formed in the rear cover and the rotor and nothing is processed on the thin blade, it is possible to form an oil passage with a large cross-sectional area. Since there are few curved parts, the hydraulic oil in the high-pressure chamber can flow smoothly into the low-pressure chamber, and the pressures in the high-pressure chamber and the low-pressure chamber can be almost instantaneously equalized. For this reason, the inertia force in one rotation of the cylinder is large, and an extremely large impact pulse can be generated. iv) The entire end surface of the blade can be brought into full contact with the rear cover, so good sealing properties can be obtained at the contact surface, effectively preventing hydraulic oil from leaking from the high-pressure chamber to the low-pressure chamber. can do.

v) Since there is no direction in the installation of the blade, the assembly of the pulse wrench can be facilitated. Brief Description of Drawings

FIG. 1 is a partially cutaway front view showing an embodiment of a pulse wrench according to the present invention, FIG. 2 is an enlarged sectional view showing a striking pulse generating mechanism of the pulse wrench of FIG. 1, and FIG. -Cross-sectional view along line III, Fig. 4 is a cross-sectional view along line IV-IV in Fig. 2, Fig. 5 is a cross-sectional view along line V-V in Fig. 2, and Fig. 6 is the state shown in Fig. 4. Fig. 7 is a cross-sectional view showing a state in which the cylinder is rotated 90 ° from the state shown in Fig. 6, Fig. 7 is a cross-sectional view showing a state in which the cylinder is further rotated 180 ° from the state in Fig. 6, and Fig. 8 is a diagram showing the oil passage and the communication passage. FIG. 9 is a partially cutaway plan view showing a communication state, and FIG. 9 is a partially cutaway plan view showing a non-communication state of an oil passage and a communication passage. FIG. 10 is an exploded perspective view showing a rotor and a cover. It is sectional drawing which shows other embodiment of the pulse wrench which concerns on invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in Fig. 1, the wrench body 1 has a handle 2, and when the operation lever 3 provided on the handle 2 is gripped, compressed air is supplied into the wrench body 1 and incorporated into the wrench body 1. The rotor 5 of the air motor 4 is rotated.

The hydraulic blow pulse generating mechanism 10 is connected to the mouth 5.

The striking pulse generating mechanism 10 has a cylinder 11 connected to the mouth 5 of the air motor 4 and rotating integrally with the mouth 5. As shown in FIG. 2, the cylinder 11 is composed of an outer cylinder 12 and an inner cylinder 13 fitted inside the outer cylinder 12. Both ends of the inner cylinder 13 have a front cover 14 and a rear cover 1. 5 and the pair of covers 14, 15 and the inner cylinder 13 are connected to the outer cylinder 12 by tightening the presser lid 16 screwed to the inner periphery of one end of the outer cylinder 12. It is pressed against an inward flange 17 provided at the end and integrated with the outer cylinder 12.

As shown in FIGS. 1 and 2, the rear cover 15 located on the air motor side of the cylinder 11 is composed of a first cover 15a and a second cover 15b, and is disposed on the air motor 4 side. A square hole 18 is formed in the second cover 15 b, and a square shaft portion 5 a provided at an end of the rotor 5 is fitted into the square hole 18. Therefore, when the mouth 5 rotates, the cylinder 11 also rotates integrally.

In addition, a pin hole 19 is formed in each of the abutting surfaces of the first cover 15a and the inner cylinder 13 and the inner cylinder 13 and the second cylinder 13 are formed by pins 20 inserted into the pin holes 19. The cover 15a is relatively stopped. Although not shown, turn between the first cover 15a and the second cover 15b as well. Has been stopped.

As shown in FIG. 3, a substantially oval cylinder chamber 21 is formed inside the inner cylinder 13, and the cylinder chamber 21 is filled with hydraulic oil.

As shown in FIG. 2, the front cover 14 has an anvil insertion hole 22, and an anvil 23 protrudes from the anvil insertion hole 22.

As shown in FIGS. 2 and 3, the anvil 23 is provided with a circular opening 23 a rotatable in the cylinder chamber 21 of the cylinder 11, and the rotor 2 3 A pair of blade insertion holes 24 that are elongated in the axial direction and open at opposing positions on the outer periphery are formed in 3a. A pair of sealing ridges 25 that are long in the axial direction are provided on the outer periphery of the rotor portion 23 a at positions 90 ° in the circumferential direction from the center of each opening of the blade insertion hole 24. ing. The seal ridges 25 are formed by providing recesses 26 on the outer periphery between each seal ridge 25 and the opening of the blade insertion hole 24.

Two blades 27 are inserted into the blade insertion holes 24, and each blade 27 is directed toward the inner periphery of the cylinder chamber 21 by an elastic body 28 incorporated between the blades 27. It is energized.

On the inner peripheral surface of the cylinder chamber 21 of the cylinder 11, four seal protrusions 29 extending long in the axial direction are formed at the opposed position in the long axis direction and the opposed position in the short axis direction, respectively. When the cylinder 11 is relatively rotated with respect to, the seal ridges 25 of the mouth 23 and the outer surfaces of the blades 27 simultaneously contact the four seal ridges 29 at the same time. As shown in FIG. 6, two high-pressure chambers H and two low-pressure chambers L are formed in the cylinder chamber 21. The state in which the high-pressure chamber H and the low-pressure chamber L are formed is a striking pulse generation state, and is formed twice during one rotation of the cylinder 11.

Here, in order to prevent the pressure in the high-pressure chamber H from rising above a predetermined pressure, and to prevent the cylinder 11 from being opened when the cylinder 11 rotates relative to the ambil 23, As shown in FIGS. 2 and 6, a passage 30 communicating the high pressure chamber H and the low pressure chamber L is provided in the inner cylinder 13, and a relief valve 31 is incorporated in the passage 30, and the inside of the high pressure chamber H When the pressure becomes higher than the set pressure of the relief valve 31, the relief valve 31 allows the hydraulic oil in the high-pressure chamber H to flow to the low-pressure chamber L.

As shown in FIGS. 6 and 10, the second cover 15b of the rear cover 15 located on the air motor side of the cylinder 11 has a first arcuate surface on the surface that abuts the first cover 15a. The hole 32 and the second arc-shaped hole 33 are formed at opposing positions, and the length of the second arc-shaped hole 33 in the circumferential direction is the circumference of the first arc-shaped hole 32. It is longer than the direction length.

The first cover 15a is formed with four oil passage holes 34 formed of axial holes communicating with both ends of the first arc-shaped hole 32 and both ends of the second arc-shaped hole 33, respectively. ing.

On the other hand, as shown in FIG. 4, the surface of the anvil 23 where the first cover 15 a of the mouth portion 23 a contacts the first cover 15 a has four communication passages at positions corresponding to the oil holes 34. 3 5 is formed. Each of the communication passages 35 has a pair of oil passages 34 communicating with both ends of each of the arc-shaped holes 32, 33 at each rotation of the cylinder 11, one of which is in the high-pressure chamber H, and the other is in the low-pressure chamber L. Will be able to communicate with The pulse wrench shown in the embodiment has the above structure.For example, when tightening a port using the pulse wrench, a socket is attached to the tip of the anvil 23 and the socket is attached to the bolt head. The rotor 5 of the air motor 4 is rotated by engaging and depressing the operation lever 3.

When the mouth 5 rotates, the rotation of the rotor 5 is transmitted to the anvil 23 through the hydraulic oil and the blade 27 filled in the cylinder 11 and the cylinder chamber 21, and the rotation of the pill 23 This tightens the port.

When the port is tightened to a predetermined torque and the rotation resistance of the port exceeds the tightening torque and the anvil 23 stops, the cylinder 11 rotates relative to the anvil 23. For each 180 ° rotation of the cylinder 11, a pair of seal ridges 25 on the outer surface of the pair of blades 27 and the outer periphery of the rotor portion 23 a were formed on the inner periphery of the cylinder chamber 21. As shown in FIGS. 6 and 7, two high-pressure chambers H and two low-pressure chambers L are formed in the cylinder chamber 21 by sliding contact with each of the four seal ridges 29. A striking pulse is generated.

This striking pulse generation state is formed twice during one rotation of the cylinder 11, but in one of these impact pulse generation states, as shown in Figs. 6 and 8, it is attached to the first cover 15a. Each of the four oil passage holes 34 communicates with the four communication passages 35 provided in the rotor portion 23a.

For this reason, the high-pressure chamber H and the low-pressure chamber L on the left and top and the low-pressure chamber L and the high-pressure chamber H on the right and bottom shown in FIG. The hydraulic oil in the high-pressure chamber H flows instantaneously to the low-pressure chamber L, and no impact pulse is generated.

The cylinder 11 is further rotated 180 ° from the state shown in FIG. 6 to form two high-pressure chambers H and two low-pressure chambers L in the cylinder chamber 21 as shown in FIG. When the striking pulse is generated, the four covers formed on the first cover 15a as shown in Figs. 7 and 9 The oil communication hole 34 and the four communication passages 35 formed in the rotor portion 23a are in a non-communication state in which they are displaced in the circumferential direction. For this reason, the blade 27 is hit by the high-pressure hydraulic oil in the high-pressure chamber H, and a shocking rotational force is applied to the anvil 23.

When the blade 27 is hit, since the volumes of the two high-pressure chambers H formed in the cylinder chamber 21 are equal, the pressure between the two high-pressure chambers H is equal, and the two blades 27 have the same force. You will be hit. Therefore, the anvil 23 rotates in a well-balanced manner. The oil passage connecting the high-pressure chamber H and the low-pressure chamber L has a simple configuration consisting of arcuate holes 32, 33, oil passage holes 34, and communication passages 35. The hydraulic oil in the high-pressure chamber H can be smoothly transferred to the low-pressure chamber L when the impact pulse is generated as shown in Figs. It can be fluidized.

As a result, the pressure difference between the high-pressure chamber H and the low-pressure chamber L can be almost instantaneously equalized, the rotation of the cylinder 11 is smooth and the inertia force is large, and a large striking pulse is generated when a striking pulse is generated. Can be generated.

Furthermore, since the blade 27 does not have an oil passage communicating the high-pressure chamber H and the low-pressure chamber L, the entire end face of the blade 27 must be brought into full contact with the end face of the first cover 15a. Can be. Therefore, good sealing properties can be obtained at the contact surface, and leakage of hydraulic oil from the high-pressure chamber H to the low-pressure chamber L can be effectively prevented.

In addition, since there is no direction in the installation of the blade 27, the assembly of the pulse wrench can be facilitated.

In the embodiment, the rear cover 15 is divided into the first cover 15a and the second cover 15b, and the second cover 15b is formed with the arc-shaped holes 32, 33. Arc-shaped holes 32, 33 may be formed on the abutment surface of the cover 15a with the second cover 15b. In this case, the overall length of the oil passage can be further reduced. Further, the rear cover 15 may be one.

Further, the communication passage 35 formed of a hole is formed in the low-end portion 6a, but the communication passage 35 formed of a groove may be formed.

As shown in FIG. 2, the cylinder 11 was formed by an outer cylinder 12, an inner cylinder 13, a front cover 14 and a rear force bar 15, but as shown in FIG. Alternatively, the cylinder 11 may be formed by the cylinder body 11 a in which the inner cylinder 13 and the front cover 14 are integrated and the rear cover 15.

Claims

The scope of the claims

1. A hydraulic striking pulse generating mechanism is connected to the mouth rotated by the compressed air, and the striking pulse generating mechanism has a front and rear cover, and a cylinder whose cover is connected to the rotor, and The front end protrudes from the front cover, the rear end is supported by the rear cover, and the center part is an anvil consisting of a mouth located inside the cylinder, and is inserted into the blade insertion hole formed in the rotor part. The cylinder has two blades that can move in the radial direction of the mouth and an elastic body that urges each blade toward the inner peripheral surface of the cylinder. Two equal-volume high-pressure chambers and two equal-volume low-pressure chambers are formed inside the cylinder for each rotation, and the hydraulic oil in the high-pressure chamber flows from the oil passage to the low-pressure chamber for each rotation of the cylinder relative to the anvil. Pulse wrench In the oil passage, a pair of arc-shaped holes having different circumferential lengths formed at opposing positions on a circumference centered on the axis of the rear cover, and a pair of arc-shaped holes from an inner surface of the rear cover. It consists of four oil passages communicating with both ends, and four communication passages provided at positions opposite to the oil passage holes at the ends facing the rear force bar of the anvil. A pulse wrench characterized in that one of two oil passages communicating with both ends of an arc-shaped hole communicates with a high-pressure chamber and the other communicates with a low-pressure chamber.

2. The rear cover is composed of a first cover and a second cover abutted with each other, and a pair of arc-shaped holes are formed in one of the abutting surfaces of the first cover and the second cover. The pulse wrench according to claim 1, wherein an oil passage is formed in the first cap on the side.