CN214265385U

CN214265385U - Pneumatic wrench

Info

Publication number: CN214265385U
Application number: CN202120045119.6U
Authority: CN
Inventors: 庄世良
Original assignee: Ningbo Xinxing Pneumatic Goods Co ltd
Current assignee: Ningbo Xinxing Pneumatic Goods Co ltd
Priority date: 2021-01-08
Filing date: 2021-01-08
Publication date: 2021-09-24
Anticipated expiration: 2031-01-08

Abstract

The utility model discloses a pneumatic wrench, which comprises a body, wherein the inside of the body is provided with a left air inlet channel, a right air inlet channel and an air outlet channel; the hole mask of the exhaust duct is provided with a silencer which is fixedly sleeved on the handle part of the body; the tail end of the handle part of the body is connected with a handle which is convenient to hold by hand, an air inlet joint which is used for being connected with a compressed air supply pipe is arranged in the handle, and a switch valve group which is used for controlling the on-off of compressed air inlet is arranged at the inner end of the air inlet joint; the handle part of the body is matched with a speed regulating knob which is used for rotationally driving the air inlet valve group to select one of the left and right air inlet channels to inlet air, and the handle is provided with a trigger which presses the control switch valve group to open. The utility model discloses small, compact structure and can reduce noise pollution, use in being suitable for the little occasion of spatial position very much.

Description

Pneumatic wrench

Technical Field

The utility model relates to a pneumatic tool's technical field especially relates to a pneumatic spanner.

Background

Pneumatic wrenches are widely used in many industries, such as automobile repair, heavy equipment maintenance, product assembly, etc., as a tool powered by compressed air to provide high torque output. However, the conventional pneumatic wrench is generally noisy, and if the wrench works in the high-noise environment for a long time, the health of people can be affected.

Disclosure of Invention

The utility model aims to solve the technical problem that to the current situation of above-mentioned prior art, and provide convenient to use, torque output are stable, and can reduce noise pollution's a pneumatic wrench.

The utility model provides a technical scheme that above-mentioned technical problem adopted does:

a pneumatic wrench comprises a body, wherein a left air inlet channel and a right air inlet channel and an air outlet channel are processed inside the body, an air cylinder and a hammering group driven by the air cylinder to rotate are arranged in an air cylinder cavity formed in the head of the body to realize torque output, a valve cavity communicated with the left air inlet channel and the right air inlet channel is formed in the handle of the body, and an air inlet valve group for realizing forward and reverse rotation control of the air cylinder by selecting air inlet of the left air inlet channel or air inlet of the right air inlet channel in the left air inlet channel and the right air inlet channel is installed in the valve cavity; the hole mask of the exhaust duct is provided with a silencer for eliminating noise, and the silencer is fixedly sleeved on the handle part of the body; the tail end of the handle part of the body is connected with a handle which is convenient to hold by hand, an air inlet joint which is used for being connected with a compressed air supply pipe is arranged in the handle, and a switch valve group which is used for controlling the on-off of compressed air inlet is arranged at the inner end of the air inlet joint; the handle part of the body is matched with a speed regulating knob which is used for rotationally driving the air inlet valve group to select one of the left and right air inlet channels to inlet air, and the handle is provided with a trigger which presses the control switch valve group to open.

In order to optimize the technical scheme, the specific measures adopted further comprise:

the cylinder comprises a cylinder body consisting of a cylinder barrel, an upper end plate and a lower end plate and a rotor which is rotatably supported and installed in the cylinder body through an upper bearing and a lower bearing; the cylinder body sequentially penetrates through the upper end plate, the cylinder barrel and the lower end plate through a cylinder positioning pin to be positioned and installed on the upper part of the cylinder cavity in a rotation-proof manner; the upper bearing is positioned and installed in an upper bearing installation cavity formed in the upper end plate, the lower bearing is positioned and installed in a lower bearing installation cavity formed in the lower end plate, the inner ring of the upper bearing is matched with the upper end of the rotor in a sleeved mode, the inner ring of the lower bearing is matched with the lower end of the rotor in a sleeved mode, and six blades are installed on the circumferential surface of the rotor in an equal radian mode.

The hammering group is arranged at the lower part of the cylinder and is formed by matching and assembling a hammering chamber, a hammering block, an impact pin and an impact rod; the upper end of the hammering chamber is formed with a spline hole, the lower end of the rotor is formed with spline teeth which are meshed with the spline hole of the hammering chamber and used for driving the hammering chamber to rotate, the hammering block is limited and clamped in the hammering chamber through an impact pin, the impact rod is positioned and sleeved in an impact rod positioning hole formed in the hammering block, the lower end of the impact rod extends out of a lower cavity opening of a cylinder cavity, and an oil-containing bearing which is matched with the impact rod in a rotating and sleeving manner is installed in the lower cavity opening.

An upper cover is arranged on an upper cavity opening of the cylinder cavity of the body through an upper cover plate bolt sealing cover, and a sealing gasket for sealing is arranged between the upper cover and the upper cavity opening in a gasket manner; the head of body below is furnished with the protective sheath.

The air inlet valve group consists of an air inlet valve block, a valve block spring and a connecting screw; the air inlet valve block is arranged at the bottom of the valve cavity, two valve block sealing rings are sleeved on the air inlet valve block, the connecting screw is spirally arranged in a cavity opening of the valve cavity, an annular shoulder formed by the connecting screw is matched with an inner ring step surface of the handle in a positioning mode, and a valve block spring is elastically pressed between the air inlet valve block and the connecting screw.

A silencer sealing ring is pressed between the silencer and the handle part of the body, and a positioning pin for preventing the silencer from moving back and forth is arranged on the handle part of the body; the speed regulation knob is fixedly provided with a pull rod for driving the air inlet valve block to rotate, and the pull rod penetrates through an arc-shaped channel formed in the handle part of the body and is connected with the air inlet valve block.

A top sleeve blind hole is radially formed on the handle part of the body, and a top sleeve device for increasing the hand feeling of the manual rotation speed regulation knob is arranged in the top sleeve blind hole; the top sleeve device comprises a top sleeve which is in sliding top connection fit with the inner wall of the speed regulation knob and a top sleeve spring which is pressed in the blind hole of the top sleeve through the top sleeve, and a guide channel which is in sliding guide fit with the top sleeve is formed on the inner wall of the speed regulation knob.

The air inlet joint is sleeved with a joint sealing ring which is in sealing fit with the inner wall of the handle, the joint sealing ring comprises a front joint sealing ring and a rear joint sealing ring, and a cylindrical pin for preventing the air inlet joint from falling off the handle is inserted in the handle; the switch valve group is positioned and clamped in a switch valve cavity formed at the inner end of the air inlet connector through a check ring for a hole.

The switch valve group comprises a switch valve, a switch valve seat and a switch valve spring; the switch valve spring, the switch valve and the switch valve seat are sequentially pressed in the switch valve cavity of the air inlet connector, and the switch valve seat is sleeved with the valve seat sealing ring.

One end of the trigger is hinged on the handle through an elastic cylindrical pin, the free end of the trigger is connected with a switch pin which penetrates into the handle in a sliding mode, and the inner end of the switch pin is connected with a valve rod of the switch valve.

Compared with the prior art, the utility model discloses be equipped with the muffler at the gauze mask of pneumatic wrench exhaust duct, the noise cancelling function that can utilize the muffler reduces the noise that pneumatic wrench during operation produced to reduce environmental noise pollution. The utility model discloses still be furnished with the speed governing knob at the stalk portion of body cover, can rotate the direction of admitting air that drives the valves of admitting air and change compressed air through the speed governing knob to the positive reverse rotation of control cylinder. The utility model discloses still install the trigger on the handle, can utilize the trigger to pass through the break-make of control switch valves control compressed air supply, the trigger adopts the push type operation, convenient operation is nimble.

The utility model discloses small, compact structure and can reduce noise pollution, use in being suitable for the little occasion of spatial position very much.

Drawings

FIG. 1 is a cross-sectional structural view of the present invention;

FIG. 2 is an enlarged view of a portion of FIG. 1 in the direction B-B;

fig. 3 is an exploded view of the present invention;

fig. 4 is a front view of the present invention;

FIG. 5 is a top view of FIG. 4;

fig. 6 is a bottom view of fig. 4.

Detailed Description

Embodiments of the present invention are described in further detail below with reference to the accompanying drawings.

Fig. 1 to 6 are schematic structural views of the present invention.

Wherein the reference numerals are: the air conditioner comprises a top sleeve D1, a top sleeve spring D2, an upper cover plate bolt L, a hole check ring Q, an air inlet joint T, a joint seal ring T1, a cylindrical pin Y, a body 1, an air inlet duct 1a, an air outlet duct 1b, an upper cover 11, a protective sleeve 12, a sealing gasket 13, a silencer 2, a silencer seal ring 21, a positioning pin 22, a handle 3, a speed regulation knob 4, a pull rod 41, a trigger 5, an elastic cylindrical pin 51, a switch pin 52, a switch valve 61, a switch valve seat 62, a switch valve spring 63, a valve seat seal ring 64, a cylinder 71, an upper end plate 72, a lower end plate 73, an upper bearing 74, a lower bearing 75, a rotor 76, a blade 77, a cylinder positioning pin 78, a hammering chamber 81, a hammering block 82, an impact pin 83, an impact rod 84, an oil-containing bearing 85, an air inlet valve block 91, a valve block spring 92, a connecting screw 93 and a valve block seal ring 94.

As shown in fig. 1 to 6, the present invention discloses a pneumatic wrench, which is small in size and compact in structure, and can reduce noise generated during operation. The pneumatic wrench comprises a body 1, wherein a left air inlet channel 1a and a right air inlet channel 1a and a left air outlet channel 1b are machined in the body 1, and the body 1 is formed with a head and a handle part integrally connected to one side of the head. The head of the body 1 is longitudinally formed with a cylinder cavity, and a cylinder arranged in the cylinder cavity and a hammering group driven by the cylinder to rotate to realize torque output are arranged in the cylinder cavity. As can be seen from fig. 1 and 2, a valve cavity is axially formed in the handle portion of the body 1, the left and right air inlet channels 1a are communicated with the valve cavity, an air inlet valve group for controlling compressed air to enter the air inlet channels 1a is installed in the valve cavity, and the air inlet valve group can determine whether the compressed air enters the left air inlet channel of the left and right air inlet channels 1a or the right air inlet channel of the left and right air inlet channels 1a through forward and reverse rotation, namely, the direction of supplying air to the cylinder is selected through rotation, so that the forward and reverse rotation of the cylinder is controlled. The exhaust gas formed by the compressed air doing work is discharged through an exhaust duct 1b, the exhaust duct 1b is communicated with a cylinder cavity, the exhaust duct 1b extends downwards in an inclined mode, and an orifice of the exhaust duct 1b is arranged below a handle part of the body 1. In order to reduce and eliminate the noise that produces when exhausting, the utility model discloses be equipped with the muffler 2 that is used for the noise elimination at exhaust duct 1 b's gauze mask, the fixed suit of this muffler 2 is on the stalk portion of body 1. As can be seen from fig. 1, two muffler seal rings 21 are also press-fitted between the muffler 2 and the handle portion of the body 1, and the two muffler seal rings 21 include a front muffler seal ring having a relatively large diameter and a rear muffler seal ring having a relatively small diameter. And in order to prevent the silencer 2 from moving back and forth on the handle part of the body 1, a positioning pin 22 is positioned and clamped on the handle part of the body 1. The positioning pin 22 is in limit fit with the rear annular surface of the silencer 2.

The utility model discloses have at the trailing end connection of 1 stalk portion of body and be used for convenient handheld hollow handle 3, handle 3 has the one deck rubber layer in the position department cladding that lies in the staff to grip, is equipped with air inlet joint T in handle 3's hollow chamber to make things convenient for people to utilize air inlet joint T to be connected with compressed air's air supply pipe. The inner end of the air inlet joint T, namely the other end connected with the air supply pipe, is expanded to form a switch valve cavity, and a switch valve group is arranged in the switch valve cavity in an anti-dropping and clamping mode through a check ring Q. The switch valve group is a valve switch and is used for controlling the on-off of compressed air supply.

The utility model discloses can also be rotational ground suit have speed governing knob 4 on the stalk portion of body 1, the forward reverse rotation of the valves that admits air is driven by speed governing knob 4's rotation, and the valves that admits air is admitted air all the way in two way inlet channels about the selection of two ways of the rotatory drive of speed governing knob 4. The handle 3 is also provided with a trigger 5 for pressing the switch valve group to open.

In the embodiment, the cylinder of the present invention includes a cylinder case 71, an upper end plate 72, and a lower end plate 73, and a rotor 76 rotatably supported by the upper bearing 74 and the lower bearing 75 and installed in the cylinder case. The cylinder body passes through the upper end plate 72, the cylinder barrel 71 and the lower end plate 73 in sequence through a cylinder positioning pin 78 and is positioned and installed on the upper part of the cylinder cavity in a rotation-proof manner. As can be seen from the sectional view of fig. 1, two exhaust holes are formed on the circumferential surface of the rear portion of the cylinder tube 71 for allowing exhaust gas to be discharged into the cylinder chamber, so that the exhaust gas discharged from the cylinder can be introduced into the exhaust port 1b through the cylinder chamber. The utility model discloses an upper bearing 74 location is installed in the fashioned upper bearing installation cavity of upper end plate 72, and lower bearing 75 location is installed in the fashioned lower bearing installation cavity of lower end plate 73, and the inner circle of upper bearing 74 cooperatees with the upper end suit of rotor 76, and the inner circle of lower bearing 75 cooperatees with the lower extreme suit of rotor 76, and six blades 77 are installed to the first radian on rotor 76 global.

In the embodiment shown in fig. 1, the hammering set of the present invention is disposed at the lower part of the cylinder, and the hammering set is formed by assembling a hammering chamber 81, a hammering block 82, an impact pin 83 and an impact rod 84. The upper end of the hammering chamber 81 is formed with a spline hole, the lower end of the rotor 76 is formed with a spline tooth which is engaged with the spline hole of the hammering chamber 81 and is used for driving the hammering chamber 81 to rotate, the hammering block 82 is limited and clamped in the hammering chamber 81 through an impact pin 83, an impact rod 84 is positioned and sleeved in an impact rod positioning hole formed in the hammering block 82, the lower end of the impact rod 84 extends out of a lower cavity opening of a cylinder cavity, and an oil-containing bearing 85 which is matched with the impact rod 84 in a rotating and sleeving manner is installed in the lower cavity opening.

In the embodiment, the upper cavity opening of the cylinder cavity of the body 1 of the utility model is provided with an upper cover 11 through an upper cover plate bolt L, and a sealing gasket 13 for sealing is arranged between the upper cover 11 and the upper cavity opening; a protective sleeve 12 is sleeved under the head of the body 1. The utility model discloses the bottom surface shaping of upper cover 11 has left inlet channel way and right inlet channel way, and left inlet channel way is linked together with the left inlet channel in the body 1, and right inlet channel way is linked together with the right inlet channel in the body 1. Compressed air can enter the cylinder body through the left air inlet channel or the right air inlet channel.

In the embodiment, as shown in fig. 1 and fig. 2, the intake valve set of the present invention is composed of an intake valve block 91, a valve block spring 92 and a connecting screw 93; the air inlet valve block 91 is arranged at the bottom of the cavity of the valve cavity, two valve block sealing rings 94 are sleeved on the air inlet valve block 91, a connecting screw 93 is spirally arranged in the cavity opening of the valve cavity, and an annular shoulder formed by the connecting screw 93 is matched with the inner ring step surface in the hollow cavity of the handle 3 in a positioning mode. The block spring 92 is elastically press-fitted between the intake valve block 91 and the connection screw 93. The handle 3 of the utility model is fixedly connected with the handle part of the body 1 through the connecting screw 93. The utility model discloses a fixed mounting has on the speed governing knob 4 and is used for driving inlet valve piece 91 pivoted dead man 41, and this dead man 41 passes the arc channel that 1 stalk portion of body was opened and is connected with inlet valve piece 91. The angle of the speed regulation knob 4 rotating forward and backward is determined by the radian of the arc-shaped channel opened by the body 1.

In the embodiment, a handle part of the body 1 is radially formed with a top sleeve blind hole, and a top sleeve device for increasing hand feeling of the manual rotation speed regulation knob 4 is arranged in the top sleeve blind hole; the jacking sleeve device comprises a jacking sleeve D1 in sliding jacking fit with the inner wall of the speed regulation knob 4 and a jacking sleeve spring D2 pressed in a blind hole of the jacking sleeve through a jacking sleeve D1, the spring force of the jacking sleeve spring D2 acts on the jacking sleeve D1, the jacking sleeve D1 is always in jacking fit with the inner wall of the speed regulation knob 4, and a guide channel in sliding guide fit with the jacking sleeve D1 is processed on the inner wall of the speed regulation knob 4.

In the embodiment, the air inlet joint T is sleeved with a joint sealing ring T1 which is in sealing fit with the inner wall of the handle 3, the joint sealing ring T1 comprises a front joint sealing ring and a rear joint sealing ring, and the handle 3 is inserted with a cylindrical pin Y for preventing the air inlet joint T from falling off the handle 3.

In the embodiment, the switching valve set of the present invention comprises a switching valve 61, a switching valve seat 62 and a switching valve spring 63; the switch valve spring 63, the switch valve 61 and the switch valve seat 62 are sequentially pressed in the switch valve cavity of the air inlet joint T, and the switch valve seat 62 is sleeved with a valve seat sealing ring 64.

In the embodiment, one end of the trigger 5 is hinged on the handle 3 through an elastic cylindrical pin 51, the free end of the trigger 5 is connected with a switch pin 52 which is slidably inserted into the handle 3, and the inner end of the switch pin 52 is connected with a valve rod of a switch valve 61.

The utility model discloses when using, the outer end of air inlet joint T is connected with compressed air's air supply pipe, and like this, when pressing trigger 5, trigger 5 can push switch valve 61 through swizzle 52 and compress switch valve spring 63, makes switch valve 61 break away from switch disk seat 62, opens switch disk seat 62's central through-hole, and compressed air enters into the valves that admit air through switch disk seat 62.

When the speed regulation knob 4 is rotated counterclockwise, the speed regulation knob 4 drives the air inlet valve block 91 of the air inlet valve group to rotate counterclockwise through the pulling rod 41, the air inlet valve block 91 rotates to open the orifice of the right air inlet duct, so that compressed air enters the air cylinder through the right air inlet duct and the right air inlet channel of the upper cover 11, the rotor 76 of the air cylinder drives the hammering group to rotate clockwise, and the impact rod 84 of the hammering group rotates clockwise to work.

When the speed regulation knob 4 is rotated clockwise, the speed regulation knob 4 drives the air inlet valve block 91 of the air inlet valve group to rotate clockwise through the pulling rod 41, the air inlet valve block 91 rotates to open the orifice of the left air inlet channel, so that compressed air enters the air cylinder through the left air inlet channel of the left air inlet channel and the left air inlet channel of the upper cover 11, the rotor 76 of the air cylinder drives the hammering group to rotate anticlockwise, and the impact rod 84 of the hammering group rotates anticlockwise to work.

While the preferred embodiments of the present invention have been illustrated, various changes and modifications may be made by those skilled in the art without departing from the scope of the present invention.

Claims

1. The utility model provides a pneumatic wrench, includes body (1) that inside processing has about two way air intake duct (1a) and exhaust duct (1b) of the same kind, the cylinder that is equipped with in the fashioned cylinder chamber of head of body (1) with receive the rotatory hammering group that realizes the output of moment of torsion of this cylinder drive, characterized by: a valve cavity communicated with the left and right air inlet channels (1a) is formed in the handle part of the body (1), and an air inlet valve group for realizing the forward and reverse rotation control of the cylinder by selecting the air inlet of the left air inlet channel or the air inlet of the right air inlet channel in the left and right air inlet channels (1a) is installed in the valve cavity; the orifice cover of the exhaust duct (1b) is provided with a silencer (2) for eliminating noise, and the silencer (2) is fixedly sleeved on the handle part of the body (1); the tail end of the handle part of the body (1) is connected with a handle (3) convenient to hold by hand, an air inlet joint (T) used for being connected with a compressed air supply pipe is arranged in the handle (3), and a switch valve bank used for controlling the on-off of compressed air inlet is installed at the inner end of the air inlet joint (T); the handle part of body (1) handle portion cover be furnished with and be used for the rotatory speed governing knob (4) that drive the air intake valve group and select one way of air inlet in two ways air inlet duct about, handle (3) on install trigger (5) that press control switch valves and open.

2. A pneumatic wrench as claimed in claim 1, wherein: the cylinder comprises a cylinder barrel (71), a cylinder body formed by an upper end plate (72) and a lower end plate (73) and a rotor (76) rotatably supported and installed in the cylinder body through an upper bearing (74) and a lower bearing (75); the cylinder body sequentially passes through the upper end plate (72), the cylinder barrel (71) and the lower end plate (73) through a cylinder positioning pin (78) and is positioned and installed on the upper part of the cylinder cavity in a rotation-proof manner; the upper bearing (74) is positioned and installed in an upper bearing installation cavity formed by an upper end plate (72), the lower bearing (75) is positioned and installed in a lower bearing installation cavity formed by a lower end plate (73), the inner ring of the upper bearing (74) is sleeved and matched with the upper end of the rotor (76), the inner ring of the lower bearing (75) is sleeved and matched with the lower end of the rotor (76), and six blades (77) are installed on the peripheral surface of the rotor (76) in an equal radian mode.

3. A pneumatic wrench as claimed in claim 2, wherein: the hammering group is arranged at the lower part of the cylinder and is formed by matching and assembling a hammering chamber (81), a hammering block (82), an impact pin (83) and an impact rod (84); the upper end of the hammering chamber (81) is formed with a spline hole, the lower end of the rotor (76) is formed with a spline tooth which is meshed with the spline hole of the hammering chamber (81) and used for driving the hammering chamber (81) to rotate, the hammering block (82) is limited and clamped in the hammering chamber (81) through an impact pin (83), the impact rod (84) is positioned and sleeved in an impact rod positioning hole formed in the hammering block (82), the lower end of the impact rod (84) extends out of a lower cavity opening of a cylinder cavity, and an oil-containing bearing (85) which is matched with the impact rod (84) in a rotating and sleeving manner is installed in the lower cavity opening.

4. A pneumatic wrench as claimed in claim 3, wherein: an upper cover (11) is arranged on an upper cavity opening of the cylinder cavity of the body (1) through an upper cover plate bolt (L) in a sealing way, and a sealing gasket (13) for sealing is arranged between the upper cover (11) and the upper cavity opening in a gasket way; a protective sleeve (12) is sleeved under the head of the body (1).

5. An air wrench as claimed in claim 4, wherein: the air inlet valve group consists of an air inlet valve block (91), a valve block spring (92) and a connecting screw (93); the air inlet valve block (91) is arranged at the bottom of the cavity of the valve cavity, two valve block sealing rings (94) are sleeved on the air inlet valve block (91), the connecting screw (93) is spirally arranged in the cavity opening of the valve cavity, an annular shoulder formed by the connecting screw (93) is matched with the inner ring step surface of the handle (3) in a positioning mode, and the valve block spring (92) is elastically pressed between the air inlet valve block (91) and the connecting screw (93).

6. An air wrench as claimed in claim 5, wherein: a silencer sealing ring (21) is pressed between the silencer (2) and the handle part of the body (1), and a positioning pin (22) for preventing the silencer (2) from moving back and forth is arranged on the handle part of the body (1); the speed regulation knob (4) is fixedly provided with a pull rod (41) for driving the air inlet valve block (91) to rotate, and the pull rod (41) penetrates through an arc-shaped channel formed in the handle part of the body (1) and is connected with the air inlet valve block (91).

7. An air wrench as claimed in claim 6, wherein: a top sleeve blind hole is radially formed in the handle part of the body (1), and a top sleeve device for increasing hand feeling of the manual rotation speed regulation knob (4) is installed in the top sleeve blind hole; the ejection sleeve device comprises an ejection sleeve (D1) which is in sliding ejection connection with the inner wall of the speed regulation knob (4) and an ejection sleeve spring (D2) which is pressed in an ejection sleeve blind hole through the ejection sleeve (D1), and a guide channel which is in sliding guide fit with the ejection sleeve (D1) is formed on the inner wall of the speed regulation knob (4).

8. An air wrench as claimed in claim 7, wherein: the air inlet connector (T) is sleeved with a connector sealing ring (T1) which is in sealing fit with the inner wall of the handle (3), the connector sealing ring (T1) comprises a front connector sealing ring and a rear connector sealing ring, and a cylindrical pin (Y) for preventing the air inlet connector (T) from falling off the handle (3) is inserted into the handle (3); the switch valve group is positioned and clamped in a switch valve cavity formed at the inner end of the air inlet joint (T) through a check ring (Q) for a hole.

9. A pneumatic wrench as claimed in claim 8, wherein: the switch valve group comprises a switch valve (61), a switch valve seat (62) and a switch valve spring (63); the switching valve is characterized in that the switching valve spring (63), the switching valve (61) and the switching valve seat (62) are sequentially pressed in a switching valve cavity of the air inlet joint (T), and the switching valve seat (62) is sleeved with a valve seat sealing ring (64).

10. A pneumatic wrench as claimed in claim 9, wherein: one end of the trigger (5) is hinged on the handle (3) through an elastic cylindrical pin (51), the free end of the trigger (5) is connected with a switch pin (52) which penetrates into the handle (3) in a sliding mode in a propping mode, and the inner end of the switch pin (52) is connected with a valve rod of a switch valve (61).