JP2023177373A - Impact torque generator for hydraulic torque wrench - Google Patents

Abstract

To provide an impact torque generator for a hydraulic torque wrench which eliminates a need for blades that are constantly urged by a spring in a direction of an outer periphery of a main shaft, has low sliding resistance, is excellent in energy efficiency, has a small temperature rise of hydraulic oil to obtain stable output, and is small, simple in structure, and durable.SOLUTION: Two seal surfaces 31a, 31b of a liner 31 are formed at positions of 180° rotational symmetry of a hollow part. When the seal surfaces 31a, 31b of the liner 31 and one seal surface of each of driving blades 34a, 34b coincide with each other, the other seal surface comes into slide contact with an inner peripheral surface of the hollow part to seal, and thereby the inside of the liner 31 is divided into a high pressure chamber H and a low pressure chamber L by the driving blades 34a, 34b so that a main shaft 9 generates impact torque.SELECTED DRAWING: Figure 14

Description

The present invention relates to a striking torque generating device for a hydraulic torque wrench.

A hydraulic torque wrench using a hydraulic impact torque generating device with low noise and vibration has been developed and put into practical use as a torque wrench impact torque generating device.
FIG. 19 shows an example of this hydraulic torque wrench. The main body 1 of this hydraulic torque wrench is connected to a main valve 2 that supplies and stops high-pressure air and selectively generates impact torque in forward and reverse rotation. The high-pressure air supplied from the valves 2 and 3 drives a rotor 4 that generates rotational torque. A hydraulic impact torque generator 5 for converting the rotational torque of the rotor 4 into impact torque is provided in a front case 6 that projects from the tip of the main body 1 of the hydraulic torque wrench. This hydraulic impact torque generating device 5 includes a liner 8 provided in a liner case 7, the liner 8 filled with hydraulic oil and sealed, and one or more units attached to a main shaft 9 coaxially inserted into the liner 8. A blade insertion groove is provided, a blade B is inserted into this blade insertion groove, and the blade B is constantly urged in the direction of the outer circumferential direction of the main shaft by a spring S so as to abut against the inner peripheral surface of the liner 8. One or more sealing surfaces are formed on the outer peripheral surface. Further, the liner 8 is provided with an output adjustment mechanism 10 that adjusts the magnitude of the impact torque. By rotating the liner 8 by the rotor 4, when the plurality of seal surfaces formed on the inner peripheral surface of the liner 8 match the seal surfaces formed on the outer peripheral surface of the main shaft 9 and the blades B, the main shaft 9 It generates impact torque.

By the way, in the case of a conventional impact torque generating device for a hydraulic torque wrench, one or more blade insertion grooves are provided in the main shaft 9, a blade B is inserted into the blade insertion groove, and the blade B is inserted into the spring S. Since the main shaft is always biased in the outer circumferential direction of the main shaft and comes into contact with the inner circumferential surface of the liner 8, energy loss due to sliding resistance between the tip of the blade B and the inner circumferential surface of the liner 8 is large. The frictional heat generated by this sliding increases the temperature of the hydraulic oil, and the output of the torque wrench fluctuates due to changes in the viscosity of the hydraulic oil. In addition, since it is necessary to provide a blade insertion groove and a hole for inserting the spring S in the main shaft 9, the diameter of the main shaft 9 must be increased in order to maintain the strength of the main shaft 9. The size of the device has increased, the structure of the device has become complicated, and there have been problems with the durability of the device, such as damage to the spring S.

In order to deal with this problem, the present applicant first eliminated the vane B that is constantly biased toward the outer circumferential direction of the main shaft by the spring S from the impact torque generating device of the hydraulic torque wrench, thereby reducing sliding resistance and generating energy. We have proposed an impact torque generating device for a hydraulic torque wrench that is efficient, provides stable output with little temperature rise of hydraulic oil, is compact, has a simple structure, and is durable (see Patent Documents 1 and 2). ).

Japanese Patent Application Publication No. 7-328944 JP 2019-42919 Publication

The basic structure of this hydraulic torque wrench itself is the same as the conventional hydraulic torque wrench shown in FIG. The rotor 4 has a forward/reverse rotation switching valve 3 for selectively generating rotational torque, and the rotor 4, which generates rotational torque, is driven by high-pressure air sent from the valves 2 and 3. A hydraulic impact torque generator 5 for converting the rotational torque of the rotor 4 into impact torque is provided in a front case 6 that projects from the tip of the main body 1 of the hydraulic torque wrench.

As shown in FIGS. 1 to 6, the hydraulic impact torque generating device 5 includes a liner 11 provided in a liner case 7, the liner 11 filled with hydraulic oil and sealed, and a main shaft 9 disposed coaxially within the liner 11. Insert.

The liner 11 into which the main shaft 9 is inserted has a substantially elliptical cavity formed inside, and four sealing surfaces 11a, 11b formed in pairs in a mountain shape are formed on the inner peripheral surface of the liner 11. A pair of seal surfaces, that is, a seal surface 11a and a seal surface 11b, are formed at positions that are 180° rotationally symmetrical. This cylindrical liner 11 has its outer periphery supported by a liner case 7, and a liner upper cover 12 and a liner lower cover 13 are arranged at both ends of the liner 11, and the liner 11, liner upper cover 12, and liner lower cover 13 are , by inserting knock pins 17 into pin holes provided in the liner 11 and pin holes 12a and 13a provided in the liner upper cover 12 and liner lower cover 13, respectively, so that they rotate integrally. The liner upper cover 12 is further fixed in the axial direction by the liner case cover 7a, so that the hydraulic oil filled inside the liner 11 is sealed.

On the main shaft 9 coaxially disposed inside the liner 11, two protrusions 15a and 15b with smooth surfaces are formed at positions 180° rotationally symmetrical.
The two protrusions 15a and 15b of the main shaft 9 are formed to have shorter axial and circumferential lengths than the inner cavity of the liner 11, so that the two protrusions 15a and 15b actuate at both axial ends and the circumferential tip. It is configured to form a passage through which oil flows.

Two driving blades 14a, 14b having a smooth surface, a substantially triangular cross section, and the same size are provided in a cavity formed inside the liner 11 and partitioned by the protrusions 15a, 15b of the main shaft 9. Insert. The two driving blades 14a, 14b have an axial length that is approximately the same as the inner cavity of the liner 11 so that the side surfaces of the driving blades 14a, 14b are in sliding contact with the inner surfaces of the liner upper cover 12 and the liner lower cover 13. At the same time, a sealing surface corresponding to the sealing surfaces 11a, 11b of the liner 11 is formed near both ends of the liner 11, and the sealing surfaces 11a, 11b of the liner 11 and the driving blades 14a, 14b are formed in the vicinity of both ends thereof. Constructed so that the sealing surfaces meet twice.

The outer circumferential surface of the liner 11 is provided with a communication groove 16 that communicates with each other a hollow portion that becomes a low pressure chamber L inside the liner 11 and is defined by the driving blades 14a, 14b and the sealing surfaces 11a, 11b of the liner 11.

Further, the liner 11 is provided with an output adjustment mechanism 10 that adjusts the magnitude of the impact torque parallel to the axis of the liner 11. This output adjustment mechanism 10 is conventionally known, and is defined by a cavity section inside the liner 11 that is defined by the driving blades 14a, 14b and the sealing surfaces 11a, 11b of the liner 11, which becomes a high pressure chamber H, and a low pressure chamber L. It is composed of ports 10a and 10b that communicate with the cavity, and an output adjustment valve 10c that is adjustable and screwed into a screw hole 13b provided in the lower lid 13 of the liner.

To explain the operation of the impact torque generating device 5 of this hydraulic torque wrench, first, when the main valve 2 and the switching valve 3 are operated to introduce high pressure air into the rotor chamber in the main body 1, the rotor 4 rotates at high speed. This rotational force of the rotor is transmitted to the liner 11.

Due to the rotation of the liner 11, the inside of the liner case 7 changes as shown in FIG. 6(a)→(b)→(c).
Changes as →(d) →(a)... FIG. 6(a) shows a state in which no impact torque is generated on the main shaft 9, and FIGS. 6(b), (c), and (d) show states in which the liner 11 is rotated by approximately 90 degrees.

Impact torque is generated on the main shaft 9 when the seal surfaces 11a, 11b of the liner 11 and the seal surfaces of the driving blades 14a, 14b match, and the inside of the liner 11 is generated as shown in FIGS. The cavity is divided into four chambers, and from the shape of the cavity inside the liner 11, at the moment when impact torque is generated on the main shaft 9, the volume on the high pressure chamber H side decreases, and the volume on the low pressure chamber L side increases. , the respective chambers become a high pressure chamber H and a low pressure chamber L. That is, when the liner 11 is rotated by the rotor 4 and reaches a position where the seal surfaces 11a, 11b of the liner 11 and the seal surfaces of the driving blades 14a, 14b match, the respective chambers become a high pressure chamber H and a low pressure chamber L. By pushing the driving blades 14a, 14b toward the low pressure chamber L side, the sealing surfaces 11a, 11b of the liner 11 and the sealing surfaces of the driving blades 14a, 14b match, and the cavity inside the liner 11 is completely sealed. In this state, the rotational force of the liner 11 acts on the projections 15a, 15b of the main shaft 9 via the driving blades 14a, 14b, causing the main shaft 9 to generate impact torque. The main shaft 9 is rotated twice per rotation of the liner 11 by the impact torque generated intermittently to perform desired operations such as tightening and loosening bolts and nuts.

On the other hand, when shown in FIGS. 6(a) and 6(c), when the sealing surfaces 11a, 11b of the liner 11 and the sealing surfaces of the driving blades 14a, 14b reach a position where they match, each chamber instantly closes to the high pressure chamber H. However, as the driving blades 14a and 14b are pushed toward the low pressure chamber L, the seal surfaces 11a and 11b of the liner 11 and the seal surfaces of the driving blades 14a and 14b do not match, and the inside of the liner 11 Since the hydraulic oil in the high pressure chamber H side flows through the gap between both seal surfaces to the low pressure chamber L side without the cavity portion being in a sealed state, no impact torque is generated on the main shaft 9.

Moreover, when the rotor 4 is rotated in the opposite direction, the inside of the liner case 7 changes as shown in FIG. 6(d)→(c)→(b)→(a)→(d)... It is possible to generate impact torque on the main shaft 9 in the opposite direction.

Here, although the basic structure is the same as the above example, the hydraulic impact torque generating device 5 can also be configured as shown in FIGS. 7 to 12.

This hydraulic impact torque generating device 5 includes a liner 21 provided in a liner case 7, the liner 21 filled with hydraulic oil and sealed, and the main shaft 9 coaxially inserted into the liner 21.

The liner 21 into which the main shaft 9 is inserted has an approximately elliptical cavity formed inside, and four mountain-shaped sealing surfaces 21a, 21b formed in sets of two on the inner circumferential surface thereof. A pair of seal surfaces, that is, a seal surface 21a and a seal surface 21b, are formed at positions that are rotationally symmetrical by 180 degrees. This cylindrical liner 21 has its outer periphery supported by a liner case 7, and a liner upper cover 22 and a liner lower cover 23 are disposed at both ends of the liner 21, and the liner 21, liner upper cover 22, and liner lower cover 23 are , by inserting dowel pins (not shown) into pin holes provided in the liner 21 and pin holes 22a and 23a provided in the liner upper cover 22 and liner lower cover 23, respectively, so that they rotate integrally. The liner upper cover 22 is further fixed in the axial direction by the liner case cover 7a, so that the hydraulic oil filled inside the liner 21 is sealed. Furthermore, guide grooves 22c and 23c are formed on the inner surfaces of the liner upper lid 22 and the liner lower lid 23 so that the guide grooves 22c and 23c are eccentric to the rotation axis O of the liner 21 so that the directions of eccentricity are 180 degrees rotationally symmetrical. Further, the liner lower lid 23 is formed with a pin hole 23e and a hydraulic oil injection hole 23f. Note that by fitting a pin 28 that passes through the liner case 7 into the pin hole 23e, rotation of the liner case 7 and the liner lower cover 23 is prevented.

On the main shaft 9 disposed coaxially inside the liner 21, two protrusions 25a and 25b with smooth surfaces are formed at positions 180 degrees rotationally symmetrical. The two protrusions 25a and 25b of the main shaft 9 are formed to have shorter axial and circumferential lengths than the inner cavity of the liner 21, so that the two protrusions 25a and 25b actuate at both axial ends and the circumferential tip. It is configured to form a passage through which oil flows.

Two driving blades 24a, 24b having a smooth surface, a substantially triangular cross section, and the same size are provided in a cavity formed inside the liner 21 and partitioned by the projections 25a, 25b of the main shaft 9. Insert. The two driving blades 24a, 24b have an axial length that is approximately the same as the inner cavity of the liner 21 so that the side surfaces of the driving blades 24a, 24b are in sliding contact with the inner surfaces of the liner upper lid 22 and the liner lower lid 23. A sealing surface corresponding to the sealing surfaces 21a and 21b of the liner 21 is formed near both ends thereof, and an inner surface of the liner upper lid 22 and the liner lower lid 23 is formed on one side of the driving blades 24a and 24b. pins 27a and 27b are formed to fit into the guide grooves 22c and 23c formed in 27a, respectively, and when the seal surfaces 21a, 21b of the liner 21 and the seal surfaces of the driving blades 24a, 24b try to match twice per one rotation of the liner 21, one of these times is when the liner upper lid 22 The movement of the driving blades 24a, 24b is regulated by pins 27a, 27b of the driving blades 24a, 24b inserted into guide grooves 22c, 23c formed on the inner surface of the liner lower lid 23 eccentrically with respect to the rotation axis O of the liner 21. This prevents mating, thereby generating one impact torque on the main shaft 9 per one revolution of the liner 21.

The outer circumferential surface of the liner 21 is provided with a communication groove 26 that communicates with each other a hollow portion that becomes a low pressure chamber L inside the liner 21 and is defined by the driving blades 24a, 24b and the seal surfaces 21a, 21b of the liner 21.

Further, the liner 21 is provided with an output adjustment mechanism 10 that adjusts the magnitude of the impact torque parallel to the axis of the liner 21. This output adjustment mechanism 10 is conventionally known, and is defined by a cavity section inside the liner 21 that is defined by the driving blades 24a, 24b and the seal surfaces 21a, 21b of the liner 21, which becomes the high pressure chamber H, and a low pressure chamber L. It is composed of ports 10a and 10b that communicate with the cavity, and an output adjustment valve 10c that is adjusted from an operation hole 23b provided in the liner lower lid 23.

Further, the liner 21 is provided with an accumulator 29 parallel to the axis of the liner 21 for absorbing thermal expansion of the hydraulic oil. This accumulator 29 is composed of a piston 29a and a ventilation member 29b, and one end surface of the piston 29a is communicated with a cavity inside the liner 21 via a small accumulator hole 23d formed in the liner lower lid 23. The other end surface is configured to communicate with the atmosphere through the ventilation member 29b, the small accumulator hole 22b formed in the liner upper lid 22, and the gap between the liner upper lid 22 and the liner case lid 7a.

To explain the operation of the impact torque generating device 5 of this hydraulic torque wrench, first, when the main valve 2 and the switching valve 3 are operated to introduce high pressure air into the rotor chamber in the main body 1, the rotor 4 rotates at high speed. This rotational force of the rotor is transmitted to the liner 21.

Due to the rotation of the liner 21, the inside of the liner case 7 changes from (a) to (b) to (c) in FIG.
)→(d)→(a)... FIG. 12(a) shows a state in which no impact torque is generated on the main shaft 9, and FIGS. 12(b), (c), and (d) show states in which the liner 21 is rotated approximately 90 degrees.

Impact torque is generated on the main shaft 9 when the sealing surfaces 21a, 21b of the liner 21 and the sealing surfaces of the driving blades 24a, 24b match, and the cavity inside the liner 21 is It is divided into four chambers, and due to the shape of the cavity inside the liner 21, the moment impact torque is generated on the main shaft 9, the volume on the high pressure chamber H side decreases, the volume on the low pressure chamber L side increases, and each chamber become a high pressure chamber H and a low pressure chamber L. That is, when the liner 21 is rotated by the rotor 4 and reaches a position where the seal surfaces 21a, 21b of the liner 21 and the seal surfaces of the driving blades 24a, 24b match, the respective chambers become a high pressure chamber H and a low pressure chamber L. By pushing the driving blades 24a, 24b toward the low pressure chamber L, the sealing surfaces 21a, 21b of the liner 21 and the sealing surfaces of the driving blades 24a, 24b match, and the cavity inside the liner 21 is completely sealed. In this state, the rotational force of the liner 21 acts on the projections 25a, 25b of the main shaft 9 via the driving blades 24a, 24b, causing the main shaft 9 to generate impact torque. The main shaft 9 is rotated once per rotation of the liner 21 by the impact torque generated intermittently to perform desired operations such as tightening and loosening bolts and nuts.

On the other hand, when shown in FIG. 12(d), the seal surfaces 21a, 21b of the liner 21 and the seal surfaces of the driving blades 24a, 24b are about to match, but at this time, the inner surfaces of the liner upper lid 22 and the liner lower lid 23 The movement of the driving blades 24a, 24b is regulated by the pins 27a, 27b of the driving blades 24a, 24b, which are inserted into the guide grooves 22c, 23c formed eccentrically with respect to the rotation axis O of the liner 21. Since the cavity is not sealed, no impact torque is generated on the main shaft 9.

12(a) and (c), when the sealing surfaces 21a, 21b of the liner 21 and the sealing surfaces of the driving blades 24a, 24b reach a position where they match, each chamber instantly closes to the high pressure chamber H. However, as the driving blades 24a and 24b are pushed toward the low pressure chamber L, the seal surfaces 21a and 21b of the liner 21 and the seal surfaces of the driving blades 24a and 24b do not match, and the liner 21 Since the internal cavity is not sealed and the hydraulic oil in the high pressure chamber H flows through the gap between both sealing surfaces to the low pressure chamber L, no impact torque is generated on the main shaft 9.

Furthermore, when the rotor 4 is rotated in the opposite direction, the inside of the liner case 7 changes as shown in FIG. 12(d)→(c)→(b)→(a)→(d)... It is possible to generate impact torque on the main shaft 9 in the opposite direction.

According to the hydraulic impact torque generating device 5 shown in FIGS. 1 to 6 and 7 to 12, the spring is essential for the impact torque generating device of the conventional hydraulic torque wrench shown in FIG. It does not require a vane that constantly urges the spindle in the direction of the outer circumference, has low sliding resistance, is energy efficient, provides stable output with little temperature rise in the hydraulic oil, is compact, has a simple structure, and is durable. This has the advantage that it is possible to obtain an impact torque generating device for a hydraulic torque wrench having the following characteristics.

The present invention further improves the hydraulic impact torque generating device 5 shown in FIGS. 1 to 6 and 7 to 12, and has a simpler structure, greater durability, lower sliding resistance, and lower energy consumption. It is an object of the present invention to provide a striking torque generating device for a hydraulic torque wrench with improved efficiency.

In order to achieve the above object, the impact torque generating device for a hydraulic torque wrench of the present invention has the following features:
A liner that is rotated by a rotor and has a cavity filled with hydraulic oil and has a sealing surface protruding from the inner peripheral surface of the cavity;
a main shaft having two protrusions and coaxially disposed inside the liner;
It has two driving blades that have sealing surfaces at both ends and are inserted into the cavity of the liner filled with hydraulic oil,
In a striking torque generating device for a hydraulic torque wrench, the interior of the liner is divided into a high pressure chamber and a low pressure chamber by a driving blade, and striking torque is generated on the main shaft.
The two sealing surfaces of the liner are formed at 180° rotationally asymmetric positions in the cavity, and
The cross-sectional shape of the two protrusions of the main shaft is formed asymmetrically across the short axis,
When the sealing surface of the liner matches the sealing surface of one of the driving blades, the other sealing surface slides against the inner circumferential surface of the cavity and seals, causing the driving blade to convert the inside of the liner into a high-pressure chamber. It is characterized in that it is divided into a low-pressure chamber and one impact torque is generated on the main shaft per one rotation of the liner.

In this case, a guide groove for regulating the movement of the driving blade may be provided on the inner surface of either the liner upper cover or the liner lower cover of the liner.

According to the impact torque generating device for a hydraulic torque wrench of the present invention, the two sealing surfaces of the liner are formed at 180° rotationally asymmetric positions in the cavity, and the cross-sectional shape of the two protrusions of the main shaft is shortened. By forming the shaft asymmetrically across the shaft, one impact torque is generated on the main shaft for each revolution of the liner in both forward and reverse rotations, and a large impact torque can be generated with a small device. Can be done.

In this case, a guide groove for regulating the movement of the driving blade may be provided on the inner surface of either the liner upper lid or the liner lower lid of the liner, and the structure becomes simple. By providing a guide groove for restricting the movement of the driving blade only on the inner surface, the guide groove in the lower lid of the liner becomes unnecessary, the diameter of the main shaft can be increased, and the durability can be improved.

An example of a striking torque generating device for a hydraulic torque wrench is shown, with (a) showing a front sectional view and (b) showing an II sectional view thereof. It is a figure which shows the driving blade of the impact torque generation device of the same example. It is a figure which shows the main shaft of the impact torque generation device of the same example. It is a figure which shows the liner upper cover of the impact torque generation device of the same example. It is a figure which shows the liner lower cover of the impact torque generation device of the same example. It is a figure which shows the operation|movement of the impact torque generation device of the same example. Another example of an impact torque generating device for a hydraulic torque wrench is shown, in which (a) is a front cross-sectional view, and (b) is a cross-sectional view taken along line II-II. It is a figure which shows the driving blade of the impact torque generation device of the same example. It is a figure which shows the main shaft of the impact torque generation device of the same example. It is a figure which shows the liner upper cover of the impact torque generation device of the same example. It is a figure which shows the liner lower cover of the impact torque generation device of the same example. It is a figure which shows the operation|movement of the impact torque generation device of the same example. 1 shows an embodiment of the impact torque generating device for a hydraulic torque wrench of the present invention, in which (a) is a view showing a liner, and (b) is a view showing a liner lower cover. The main shaft of the striking torque generator of the same example is shown, (a) is a front view, (b) is a sectional view of the protrusion seen from the tip side of the main shaft, and (c) is the protrusion seen from the tip side of the main spindle. FIG. 2 is a cross-sectional view (comparative example). It is a figure which shows the operation|movement at the time of normal rotation of the impact torque generation device of the same Example. FIG. 3 is an enlarged view showing the operation of the impact torque generating device of the same embodiment during forward rotation. It is a figure which shows the operation|movement at the time of reverse rotation of the impact torque generation device of the same Example. FIG. 3 is an enlarged view showing the operation of the impact torque generating device of the same embodiment during reverse rotation. 1 is a diagram showing the entirety of a hydraulic impact wrench incorporating a conventional impact torque generating device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an impact torque generating device for a hydraulic torque wrench according to the present invention will be described based on the drawings.

13 to 18 show an embodiment of the striking torque generating device for a hydraulic torque wrench of the present invention.

This hydraulic impact torque generating device 5 is a further improvement of the hydraulic impact torque generating device 5 shown in FIGS. 1 to 6 and 7 to 12, and has a simpler structure and durability. , which has low sliding resistance and improved energy efficiency.

The basic structure is the same as the hydraulic impact torque generating device 5 shown in FIGS. 1 to 6 and 7 to 12. The liner 31 is filled with oil and sealed, and the main shaft 9 is coaxially inserted into the liner 31.

The liner 31 into which the main shaft 9 is inserted has a substantially elliptical cavity formed therein, and two chevron-shaped sealing surfaces 31a and 31b are formed on the inner peripheral surface of the liner 31 at 180° rotationally asymmetric positions.
Specifically, the sealing surface 31b is formed at a position shifted by θ1 (5 to 10°, about 7° in this embodiment) from a 180° rotationally symmetrical position with respect to the sealing surface 31a.
This cylindrical liner 31 has its outer periphery supported by a liner case 7, and a liner upper cover 32 and a liner lower cover 33 are disposed at both ends of the liner 31, and the liner 31, liner upper cover 32, and liner lower cover 33 are , by inserting dowel pins (not shown) into pin holes provided in the liner 31 and pin holes provided in the liner upper lid 32 and liner lower lid 33, respectively, so that they rotate integrally. The liner upper cover 32 is further fixed in the axial direction by the liner case cover 7a, so that the hydraulic oil filled inside the liner 31 is sealed.
Furthermore, guide grooves 32c and 33c are formed on the inner surface of the liner upper lid 32 or the liner lower lid 33, which are coaxial with the rotation axis O of the liner 31.
The guide grooves 32c and 33c may be provided on the inner surface of either the liner upper cover 32 or the liner lower cover 33. In particular, by providing the guide grooves 32c only on the inner surface of the liner upper cover 32, the liner The guide groove 33c of the lower cover 33 is no longer necessary, the diameter of the main shaft 9 can be increased, and the guide groove 32c is concentric with the rotation axis O of the liner 31, which makes the structure simple and durable. can improve sexual performance.
Additionally, grooves for releasing hydraulic oil are formed at predetermined positions on the inner surfaces of the liner upper lid 32 and the liner lower lid 33.

Here, the hydraulic impact torque generating device 5 of this embodiment differs from the hydraulic impact torque generating device 5 shown in FIGS. 1 to 6 and 7 to 12 in that the pair of seal surfaces 31a, The other sealing surface 31a', 31b' of the liner 31b, that is, the sealing surface of the liner 31 corresponding to the sealing surface of each driving blade 34a, 34b, which will be described later, is formed by the inner circumferential surface of the cavity.
The inner circumferential surface of the cavity of the liner 31 constituting the seal surfaces 31a' and 31b' has a substantially cylindrical shape, and the angle θ2 thereof is about 30° to 70°, preferably about 40° to 60° (this In the embodiment, it is formed at an angle of 50°.
As a result, by reducing the number of mountain-shaped sealing surfaces 31a and 31b to two, it is possible to substantially omit the machining process of the hollow portion of the liner 31 that forms the sealing surfaces 31a' and 31b', and the structure is improved. This makes it possible to provide a striking torque generating device for a hydraulic torque wrench that is simple and durable.

Two protrusions 35a and 35b are formed on the main shaft 9 coaxially disposed inside the liner 31 so that the cross-sectional shape thereof is asymmetrical with respect to the short axis.
Specifically, the two protrusions 35a and 35b each have a substantially triangular shape, as shown in FIG. In the example, the other protrusion 35b has a shape in which the two base angles α1 and α2 are different (in this example, α1: 68°, α2: 82°). .
In this way, by forming the cross-sectional shapes of the two protrusions 35a and 35b of the main shaft 9 asymmetrically across the short axis, the two sealing surfaces 31a and 31b of the liner 31 are placed in a 180° rotationally asymmetric position. Together with this, it is possible to generate one impact torque on the main shaft per one rotation of the liner, whether in forward or reverse rotation.
The two protrusions 35a and 35b of the main shaft 9 are formed to have both axial and circumferential lengths shorter than the cavity inside the liner 31, so that the two protrusions 35a and 35b are formed at both axial ends and at the circumferential tip. It is configured to form a passage through which hydraulic oil flows.

Two driving blades 34a, 34b having a smooth surface, a substantially triangular cross section, and the same size are provided in a cavity formed inside the liner 31 and partitioned by the protrusions 35a, 35b of the main shaft 9. Insert. The two driving blades 34a, 34b have an axial length that is approximately the same as the inner cavity of the liner 31 so that the side surfaces of the driving blades 34a, 34b are in sliding contact with the inner surfaces of the liner upper lid 32 and the liner lower lid 33. A sealing surface corresponding to the sealing surfaces 31a, 31a', 31b, and 31b' of the liner 31 is formed near both ends thereof.
Steel balls 37a and 37b are disposed on one side of the driving blades 34a and 34b to fit into guide grooves 32c and 33c formed on the inner surface of either the liner upper cover 32 or the liner lower cover 33, It is fitted into the guide groove 32c of the liner upper lid 32 (or the guide groove 33c of the liner lower lid 33) to restrict the movement of the driving blades 34a, 34b.

Here, instead of the steel balls 37a and 37b that are inserted into the guide grooves 32c (or guide grooves 33c) that guide and restrict the movement of the driving blades 34a and 34b, which are used in this embodiment, Application of pins 27a and 27b that fit into guide grooves 22c and 23c used in the hydraulic striking torque generator 5 shown in FIG. 12 that guides and regulates the movement of driving blades 34a and 34b. You can also do it.

On the outer circumferential surface of the liner 31, a cavity that becomes a low pressure chamber L inside the liner 31, which is defined by the driving blades 34a, 34b and the seal surfaces 31a, 31a', 31b, 31b' of the liner 31, is communicated with each other. A communication groove (not shown) is provided.

Further, the liner 31 is provided with an output adjustment mechanism 10 that adjusts the magnitude of the impact torque parallel to the axis of the liner 31. This output adjustment mechanism 10 is conventionally known, and includes a cavity that becomes a high-pressure chamber H inside the liner 31, which is partitioned by the driving blades 24a, 24b and the sealing surfaces 31a, 31a', 31b, 31b' of the liner 31. and a port (not shown) that communicates with the hollow portion that becomes the low pressure chamber L, and an output adjustment valve 10c that is adjustable and screwed into a screw hole provided in the liner lower cover 33.

Further, the liner 31 is provided with an accumulator 39 parallel to the axis of the liner 31 for absorbing thermal expansion of the hydraulic oil.

To explain the operation of the impact torque generating device 5 of this hydraulic torque wrench, first, when the main valve 2 and the switching valve 3 are operated to introduce high pressure air into the rotor chamber in the main body 1, the rotor 4 rotates at high speed. This rotational force of the rotor is transmitted to the liner 31.

As the liner 31 rotates, the inside of the liner case 7 changes as shown in FIG. 15(a)→(a')→(b)→(c)→(c')→(d)→(a)→... Change.

Impact torque is generated on the main shaft 9 when the seal surfaces 31a, 31a', 31b, 31b' of the liner 31 and the seals of the driving blades 34a, 34b are generated as shown in FIG. The surfaces match, and the cavity inside the liner 31 is divided into four chambers, and due to the shape of the cavity inside the liner 31, the volume on the high pressure chamber H side decreases at the moment when impact torque is generated on the main shaft 9. The volume on the low pressure chamber L side increases, and the respective chambers become a high pressure chamber H and a low pressure chamber L. That is, when the liner 31 is rotated by the rotor 4 and reaches a position where the seal surfaces 31a, 31a', 31b, 31b' of the liner 31 and the seal surfaces of the driving blades 34a, 34b match, each chamber becomes a high pressure chamber H. When the low pressure chamber L is formed, the driving blades 34a and 34b are pushed toward the low pressure chamber L, so that the seal surfaces 31a, 31a', 31b, and 31b' of the liner 31 match the seal surfaces of the driving blades 34a and 34b, The cavity inside the liner 31 is completely sealed, and the rotational force of the liner 31 acts on the protrusions 35a, 35b of the main shaft 9 via the driving blades 34a, 34b, generating impact torque on the main shaft 9. let The main shaft 9 is rotated once per rotation of the liner 31 by the impact torque generated intermittently to perform desired operations such as tightening and loosening bolts and nuts.

On the other hand, in cases other than FIG. 15(c) (FIG. 16(c)), the sealing surfaces 31a, 31a', 31b, 31b' of the liner 31 and the sealing surfaces of the driving blades 34a, 34b do not match, and the liner Since the cavity inside 31 is not sealed, no impact torque is generated on the main shaft 9.

Furthermore, when the rotor 4 is rotated in the opposite direction, the inside of the liner case 7 changes as shown in FIG. →(d)→(a)→...

Impact torque is generated on the main shaft 9 as shown in FIG. 17(c) (FIG. 18(c)), and impact torque in the opposite direction can be generated on the main shaft 9. On the other hand, as shown in FIG. In cases other than (FIG. 18(c)), no impact torque is generated on the main shaft 9.

The other configurations and functions of this hydraulic impact torque generating device 5 are the same as those of the hydraulic impact torque generating device 5 shown in FIGS. 1 to 6 and 7 to 12.

The striking torque generating device for a hydraulic torque wrench according to the present invention has been described above based on the embodiment thereof, but the present invention is not limited to the configuration described in the above embodiment. In addition to the air motor, an electric motor can also be used, and the configuration can be changed as appropriate without departing from the spirit of the invention.

The impact torque generating device of the hydraulic torque wrench of the present invention does not require a blade that is constantly biased in the direction of the outer circumference of the main shaft by a spring, has low sliding resistance, is highly energy efficient, and is stable with little temperature rise of the hydraulic oil. Because it has the characteristics of high output, small size, simple structure, and durability, it is suitable for hydraulic torque wrenches that use electric motors that cannot be expected to have the cooling effect of high-pressure air as a power source, and for high tightening accuracy. In addition to being suitable for use in required hydraulic torque wrenches, it can also be used, for example, in hydraulic torque wrenches using an air motor.

1 Main body 2 Main valve 3 Forward/reverse rotation switching valve 4 Rotor 5 Impact torque generator 6 Front case 7 Liner case 8 Liner 9 Main shaft 10 Output adjustment mechanism 11 Liner 11a Liner sealing surface 11b Liner sealing surface 12 Liner top cover 13 Liner bottom Lid 14a Driving blade 14b Driving blade 15a Main shaft protrusion 15b Main shaft protrusion 16 Communication groove 17 Dowel pin 21 Liner 21a Seal surface of liner 21b Seal surface of liner 22 Liner upper cover 22c Guide groove 23 Liner lower cover 23c Guide groove 24a Driving blade 24b Driving blade 25a Main shaft protrusion 25b Main shaft protrusion 26 Communication groove 27a Pin 27b Pin 29 Accumulator 31 Liner 31a Liner sealing surface 31a' Liner sealing surface 31b Liner sealing surface 31b' Liner sealing surface 32 Liner top cover 32c Guide groove 33 Liner lower cover 33c Guide groove 34a Driving blade 34b Driving blade 35a Main shaft projection 35b Main shaft projection 37a Steel ball 37b Steel ball 39 Accumulator H High pressure chamber L Low pressure chamber S Spring

Claims (2)

A liner that is rotated by a rotor and has a cavity filled with hydraulic oil and has a sealing surface protruding from the inner peripheral surface of the cavity;
a main shaft having two protrusions and coaxially disposed inside the liner;
It has two driving blades that have sealing surfaces at both ends and are inserted into the cavity of the liner filled with hydraulic oil,
In a striking torque generating device for a hydraulic torque wrench, the interior of the liner is divided into a high pressure chamber and a low pressure chamber by a driving blade, and striking torque is generated on the main shaft.
The two sealing surfaces of the liner are formed at 180° rotationally asymmetric positions in the cavity, and
The cross-sectional shape of the two protrusions of the main shaft is formed asymmetrically across the short axis,
When the sealing surface of the liner matches the sealing surface of one of the driving blades, the other sealing surface slides against the inner circumferential surface of the cavity and seals, causing the driving blade to convert the inside of the liner into a high-pressure chamber. 1. A striking torque generating device for a hydraulic torque wrench, characterized in that the striking torque generating device is divided into a low-pressure chamber and generates one striking torque on the main shaft per one rotation of a liner. The impact torque generation of the hydraulic torque wrench according to claim 1, characterized in that a guide groove for regulating the movement of the driving blade is provided on the inner surface of one of the liner upper cover and the liner lower cover of the liner. Device.

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