TWI870145B - Pneumatic saw - Google Patents

Abstract

A pneumatic saw includes a housing, a piston seat disposed in the housing, a piston disposed on the piston seat, and an air guide assembly. The air guide assembly is disposed in the housing and includes a reversing brake block, an air guide seat, a partition plate disposed on a side of the air guide seat facing the piston seat, and an air block ring disposed on the air guide seat. The air guide seat has an air inlet in which the reversing brake block is disposed, a plurality of main working air channels connected to the air inlet, and a plurality of auxiliary working air channels connected to the air inlet. Each of the main working air passages and the auxiliary working air passages comprises a longitudinal hole parallel to the air inlet passage, and a transverse through hole connecting the air inlet passage and the longitudinal hole. One end of the transverse through hole is shielded by the air blocking ring, and the air blocking ring is fixed to the air guide seat by a latch.

Description

Pneumatic saw

The present invention relates to a pneumatic saw.

A pneumatic saw uses a reversing module to achieve the purpose of reciprocating a saw blade. TWI428212 discloses a cylinder and reversing function module structure of a reciprocating pneumatic tool, which includes an air pressure introduction seat (the case number is 30), on which a positive air intake hole (the case number is 33), a reversing action groove (the case number is 40) connected to the positive air intake hole, two auxiliary air intake holes (the case number is 36) connected to the positive air intake hole, and two oblique through holes (the case number is 42) connected to the reversing action groove. The auxiliary air intake holes and the oblique through holes are implemented obliquely, so the air pressure introduction seat needs to be accurately aligned during production to be accurately formed, which makes production more difficult.

On the other hand, the conventional pneumatic saw further includes an air intake seat, which provides an air valve arrangement, and the air intake seat cooperates with the air pressure introduction seat at the front section. The conventional pneumatic saw has two sets of connection grooves at a position where the air intake seat is expected to be installed on a shell, and the two sets of connection grooves provide two annular parts for positioning the air intake seat. Although the two annular parts can stably limit the position of the air intake seat, they also make it difficult to disassemble the air intake seat, resulting in the problem that the pneumatic saw cannot be repaired or is difficult to repair.

The main purpose of the present invention is to solve the problem of difficulty in manufacturing the air guide seat for reversing which is usually used with a pneumatic saw.

The secondary purpose of the present invention is to solve the problems caused by the limitation means of the air intake seat using a pneumatic saw for subsequent maintenance.

To achieve the above-mentioned purpose, the present invention provides a pneumatic saw, which causes a saw blade to reciprocate when the pneumatic saw is started. The pneumatic saw comprises a hollow housing, a piston seat disposed in the housing, a piston disposed on the piston seat and used to push the saw blade, and an air guide assembly disposed in the housing. The piston seat is formed with a piston working space in which the piston is disposed, and a plurality of return channels connected to the piston working space. The air guide assembly comprises a reversing brake block, an air guide seat, a partition plate disposed on a side of the air guide seat facing the piston seat, and an air blocking ring disposed on the air guide seat. The air guide seat has an air intake passage in which the reversing brake block is arranged and connected to the piston working space, a plurality of main working air passages connected to the air intake passage, and a plurality of auxiliary working air passages connected to the air intake passage and the return passages. Each of the main working air passages and the auxiliary working air passages respectively includes a longitudinal hole parallel to the air intake passage, and a transverse through hole connecting the air intake passage and the longitudinal hole, and one end of the transverse through hole is covered by the air blocking ring. The air blocking ring is fixed to the air guide seat by a latch, and the air guide seat has a latch mounting hole for the latch to be arranged.

In one embodiment, the plurality of transverse through holes of the main working air channels are located on the same extension line, and two of the plurality of transverse through holes of the auxiliary working air channels are located on the same extension line.

In one embodiment, two of the plurality of transverse through holes of the auxiliary working airways are arranged in parallel.

In one embodiment, the air guide seat has a ventilation groove connecting the main working air passages and the air inlet passage.

In one embodiment, the air guide seat has an air vent connected to the air inlet, and the air vent is not covered by the air blocking ring.

In one embodiment, the air guide seat has a plurality of first connecting holes, the piston seat has a plurality of second connecting holes respectively connected to the first connecting holes, each of the first connecting holes is provided with a connecting piece arranged therein, and the connecting piece has a cap portion that can limit the position of the air blocking ring.

In one embodiment, the pneumatic saw has an air intake assembly that cooperates with the air guide assembly, the air intake assembly includes an air intake seat disposed in the housing, an air valve disposed in the air intake seat, and an operating rod disposed on the air intake seat and connected to the air valve. The housing has a through hole for the operating rod to pass through, the air intake seat has an air intake channel connected to the air intake channel of the air guide seat, an installation branch connected to the air intake channel, and a rod installation hole corresponding to the through hole and provided for the operating rod to be inserted. The air valve is located at the intersection of the air intake channel and the installation branch, the opening of the installation branch is assembled with a sealing member, and the air intake seat and the housing are assembled by screw connection.

In one embodiment, the pneumatic saw includes an exhaust space formed between the air intake seat and the housing, at least one muffler disposed in the exhaust space, at least one muffler limiting plate disposed on a side of the air intake seat facing the air guide seat to limit the at least one muffler to be located around the air intake seat, and a spring respectively abutting against the muffler limiting plate and the air guide seat, the muffler limiting plate having at least one through hole corresponding to the at least one muffler.

Through the above implementation of the present invention, compared with the conventional method, the following characteristics are achieved: the main working air channels and the auxiliary working air channels on the air guide seat of the present invention are not implemented with oblique holes, which reduces the difficulty and defect rate in manufacturing.

The detailed description and technical content of the present invention are as follows with the accompanying drawings: Please refer to Figures 1 to 3. The present invention provides a pneumatic saw 20, which causes a saw blade 21 to reciprocate when the pneumatic saw 20 is started. The pneumatic saw 20 includes a housing 22, a piston seat 23, a piston 24, and an air guide assembly 25. The housing 22 is hollow. The piston seat 23 is disposed in the housing 22, and the piston seat 23 is formed with a piston working space 231. The piston 24 is disposed in the piston working space 231, and the piston 24 is used to push the saw blade 21.

Referring to FIGS. 1 to 7 , the air guide assembly 25 is disposed in the housing 22. The air guide assembly 25 includes an air guide seat 251, an air blocking ring 252, a reversing brake block 253, and a partition plate 254. The air guide seat 251 has an air inlet 255, a plurality of main working air channels 256 connected to the air inlet 255, and a plurality of auxiliary working air channels 257 connected to the air inlet 255. The air guide seat 251 has a partition rib 258 formed in the air inlet 255. The partition rib 258 can divide the air inlet 255 into a first section 259 and a second section 260. The first section 259 and the second section 260 are still connected. In other words, the partition rib 258 is a ring structure formed along the inner wall of the air inlet 255. Furthermore, one end opening of each of the main working air passages 256 is connected to the first section 259 of the air inlet passage 255, and the other end opening is located on the surface of the air guide seat 251 that is expected to be assembled with the partition plate 254. On the other hand, one end opening of each of the auxiliary working air passages 257 is connected to the second section 260 of the air inlet passage 255 and can face the reversing brake block 253, and the other end opening is located on the surface of the air guide seat 251 that is expected to be assembled with the partition plate 254.

Please refer to Figures 3 and 4 again. Each of the main working air passages 256 and each of the auxiliary working air passages 257 of the present invention includes a longitudinal hole 261 (262) parallel to the air inlet passage 255, and a transverse through hole 263 (264) connecting the air inlet passage 255 and the longitudinal hole 261 (262). The longitudinal hole 261 (262) and the transverse through hole 263 (264) are formed by a drilling operation. When the drilling operation is performed, the structure of the present invention does not need to wait for the workpiece to be tilted at a special angle, which can simplify the manufacturing process and reduce the occurrence of drilling errors. Furthermore, the opening of one end of the transverse through hole 263 (264) can be directly observed from the appearance of the air guide seat 251. On the other hand, the air guide seat 251 has a ventilation groove 265 connecting the main working air passages 256 and the air inlet 255. The ventilation groove 265 is arranged on the surface of the air guide seat 251 expected to be assembled with the partition plate 254, and the opening of one end of the main working air passages 256 is located in the ventilation groove 265.

Furthermore, the air blocking ring 252 is sleeved on the air guide seat 251 and covers one end of the transverse through hole 263 (264), that is, the gas is prohibited from being discharged therefrom. Furthermore, in order to prevent the high-pressure gas flowing in the transverse through hole 263 (264) from accidentally pushing the air blocking ring 252, the air blocking ring 252 is fixed to the air guide seat 251 by a latch member 40. Furthermore, the air blocking ring 252 has a through hole 266, and the air guide seat 251 has a latch mounting hole 267 facing the through hole 266 and providing the latch member 40.

As mentioned above, the reversing brake block 253 is disposed in the second section 260 of the intake passage 255, and the reversing brake block 253 can move in the second section 260 of the intake passage 255. On the other hand, the partition plate 254 is disposed between the air guide seat 251 and the piston seat 23, and the partition plate 254 further restricts the movement of the reversing brake block 253 from leaving the second section 260 of the intake passage 255. A first air hole 268 is formed on the partition plate 254, and the first air hole 268 allows gas to enter the piston seat 23.

Please refer to Figure 4 again. In addition to forming the piston working space 231, the piston seat 23 further forms a plurality of recirculation channels 234. The number of the recirculation channels 234 is the same as the number of the auxiliary working air channels 257. One end opening of each of the recirculation channels 234 is connected to the piston working space 231, and the other end opening is indirectly connected to one of the auxiliary working air channels 257. Specifically, the partition plate 254 is disposed between the piston seat 23 and the air guide seat 251. In addition to forming the first air hole 268, the partition plate 254 further forms a plurality of second air holes 270. The second air holes 270 serve as bridges between the recirculation channels 234 and the auxiliary working air channels 257.

Please refer to Figures 3 to 6 again. In addition to the above, the pneumatic saw 20 further includes an exhaust design. The above exhaust design is to exhaust air from the end of the shell 22 away from the saw blade 21. Specifically, the pneumatic saw 20 includes an exhaust space 28 defined by at least the shell 22, the piston seat 23 and the air guide seat 251. The piston seat 23 is formed with a plurality of exhaust holes 232 connected to the piston working space 231. The exhaust of the exhaust hole 232 depends on the active position of the piston 24. Please refer to Figure 6. The air guide seat 251 is formed with a vent hole 271 connected to the second section 260 of the inlet duct 255. Further, the vent hole 271 is not covered by the air blocking ring 252.

The operation of the pneumatic saw 20 is briefly described in FIG. 3 . When the high-pressure gas enters the air inlet 255, the high-pressure gas sequentially enters the main working air channels 256 and the vent groove 265 from the first section 259 of the air inlet 255, and finally enters the piston working space 231 through the first air hole 268 of the partition plate 254, pushing the piston 24 to move away from the air guide seat 251. At the same time, the reversing brake block 253 abuts against the partition rib 258 due to the flow direction of the high-pressure gas, and shields the auxiliary working air channels 257. Furthermore, after the piston 24 moves, the high-pressure gas will be discharged into the exhaust space 28 through the exhaust holes 232 on the piston seat 23, and finally discharged from at least one end cap 29 on the end of the housing 22 away from the saw 21.

As mentioned above, please refer to FIG. 4. When the piston 24 moves away from the air guide seat 251, part of the gas in the piston working space 231 is forced to enter the recirculation channels 234 and flow to the auxiliary working air channels 257. When the recirculation gas is discharged from the auxiliary working air channels 257, it will push the reversing brake block 253 to move toward the piston seat 23. Please refer to FIG. 6. When the piston 24 is pushed to the bottom away from the air guide seat 251, the recirculation gas will disappear because the piston 24 no longer compresses the space, and the high-pressure gas that continues to intake will enter the auxiliary working air channels 257 and the recirculation channels 234, pushing the piston 24 back. The above-mentioned actions are then repeated to achieve the reciprocating displacement of the piston 24, thereby driving the saw 21 reciprocatingly.

As mentioned above, in one embodiment, the plurality of transverse through holes 263 of the main working air channels 256 are located on the same extension line, and two of the plurality of transverse through holes 264 of the auxiliary working air channels 257 are located on the same extension line. In the aforementioned embodiment, the plurality of transverse through holes 264 located on the same extension line can be drilled once in a single drilling operation to simplify the manufacturing process of the air guide seat 251. In addition to the aforementioned, in one embodiment, two of the plurality of transverse through holes 264 of the auxiliary working air channels 257 are arranged in parallel.

Referring again to FIG. 1 and FIG. 2 , in one embodiment, the gas guide seat 251 has a plurality of first connection holes 272, and the piston seat 23 has a plurality of second connection holes 233 respectively connected to the first connection holes 272. Each of the first connection holes 272 is provided with a connecting member 41 disposed therein to be assembled with one of the second connection holes 233, so that the gas guide seat 251 and the piston seat 23 form an assembly. In addition, the connecting member 41 has a cap portion 411, for example, the connecting member 41 can be a flat head bolt. On the other hand, each of the first connection holes 272 is located at a position where the vertical projection of the cap portion 411 of the connector 41 can contact the air blocking ring 252, so that the cap portion 411 can limit the position of the air blocking ring 252 when the connector 41 completes the connection between the air guide seat 251 and the piston seat 23, that is, part of the cap portion 411 presses against the end surface of the air blocking ring 252.

Referring again to FIGS. 1 to 6 , the pneumatic saw 20 further has an air intake assembly 30, which cooperates with the air guide assembly 25. The air intake assembly 30 includes an air intake seat 301, an air valve 302, and an operating rod 303. The air intake seat 301 is disposed in the housing 22, and the air intake seat 301 and the housing 22 are assembled by screw connection. Specifically, a first assembly thread 304 is formed on the outer surface of the air intake seat 301, and a second assembly thread 305 that cooperates with the first assembly thread 304 is formed on the inner wall of the housing 22. The present invention solves the problem that the positioning method used by the conventional air intake seat increases the difficulty of maintenance through the above results. Furthermore, from the appearance of the air intake seat 301, the air intake seat 301 has two chamfered planes 306 and two arcuate surfaces 307 respectively connecting the two ends of the two chamfered planes 306. After the air intake seat 301 is installed in the shell 22, the two chamfered planes 306 do not contact the shell 22, but form a hollow, which will constitute a part of the exhaust space 28. The air intake seat 301 can be assembled with a jig of the same type to assist.

Referring again to FIG. 3 and FIG. 7 , the air intake seat 301 has an air intake passage 308 connected to the air intake passage 255 of the air guide seat 251, a mounting branch 309 connected to the air intake passage 308, and a rod mounting hole 310 for inserting the operating rod 303. In addition, the air valve 302 is disposed at the intersection of the air intake passage 308 and the mounting branch 309. Specifically, the air valve 302 is inserted into the air intake seat 301 from the mounting branch 309 and is used to determine whether the air intake passage 308 is unobstructed. In addition, the opening of the installation branch channel 309 is assembled with a sealing member 311 to close the installation branch channel 309 when the gas valve 302 is installed, so as to limit the gas entering the inlet seat 301 to only use the inlet channel 308 as the only flow path. In one embodiment, the sealing member 311 and the inlet seat 301 can be assembled by screwing. Furthermore, the operating rod 303 cooperates with a pressure plate 42 disposed outside the housing 22, and the operating rod 303 and the gas valve 302 will still protrude from the housing 22 after being assembled. The housing 22 has a through hole 221 for the operating rod 303 to be inserted. The through hole 221 corresponds to the rod mounting hole 310 when the air intake seat 301 is installed in the housing 22. Please refer to Figure 7 again to explain the assembly of the operating rod 303. The operating rod 303 is not assembled at the same time as the air intake seat 301. During assembly, the air intake seat 301 is first placed in the housing 22, and when the rod mounting hole 310 and the through hole 221 are aligned, the operating rod 303 will be able to pass through the through hole 221 and penetrate into the rod mounting hole 310 until it is assembled with the air valve 302. At the same time, the purpose of the operating rod 303 is not only to control the air valve 302, but also to limit the position of the air intake seat 301.

Referring again to FIGS. 4 and 5 , in one embodiment, the pneumatic saw 20 further comprises at least one silencer 43, at least one silencer limiting plate 44, and a spring 45. The at least one silencer 43 may be a piece of cotton, and the silencer 43 is disposed in the exhaust space 28. The at least one silencer limiting plate 44 is disposed on the side of the air inlet seat 301 facing the air guide seat 251, and the at least one silencer limiting plate 44 is used to limit the at least one silencer 43 to be located only around the air guide seat 251. The at least one silencer limiting plate 44 has at least one through hole 441 disposed corresponding to the at least one silencer 43, and the through hole 441 provides passage for the gas flowing in the exhaust space 28. Furthermore, the spring 45 respectively presses against the muffler limiting plate 44 and the air guide seat 251. The force provided by the spring 45 to the muffler limiting plate 44 will make the muffler limiting plate 44 close to the air inlet seat 301 to limit the position of the at least one muffler 43.

20: Pneumatic saw

21: Saw

22: Shell

221:Through hole

23: Piston seat

231: Piston working space

232: Exhaust hole

233: Second connection hole

234: Circulation channel

24: Piston

25: Air guide components

251: Gas seat

252: Air choke ring

253: Reversing brake block

254: Partition board

255: Air intake

256: Main working airway

257: Secondary working airway

258: Rib

259: First paragraph

260: Second paragraph

261, 262: Longitudinal holes

263, 264: Horizontal through hole

265: Ventilation slot

266:Piercing

267: Latch mounting hole

268: First vent

270: Second air hole

271: Vent

272: First connection hole

28: Exhaust space

29: End cover

30: Air intake assembly

301: Intake seat

302: Air valve

303: Operating lever

304: First assembly thread

305: Second assembly thread

306: plane cutting

307: Curved surface

308: Air intake channel

309: Install the Qidao

310: Rod mounting hole

311: Closed item

40: Latch

41: Connectors

411: Hat section

42: Pressure plate

43:Silencer

44: Silencer limiting plate

441: Via

45: Spring

Figure 1 is a structural exploded view of an embodiment of the pneumatic saw of the present invention.

Figure 2 is a structural exploded view of another direction of an embodiment of the pneumatic saw of the present invention.

Figure 3 is a schematic diagram of the implementation of the pneumatic saw of the present invention (I).

Figure 4 is a schematic diagram of the implementation of the first embodiment of the pneumatic saw of the present invention (II).

Figure 5 is a schematic diagram of the implementation of the first embodiment of the pneumatic saw of the present invention (III).

Figure 6 is a schematic diagram of the implementation of the first embodiment of the pneumatic saw of the present invention (IV).

Figure 7 is a schematic diagram of the assembly of the operating rod of the first embodiment of the pneumatic saw of the present invention.

20: Pneumatic saw

21: Saw

22: Shell

23: Piston seat

232: Exhaust hole

24: Piston

251: Gas seat

252: Air choke ring

253: Reversing brake block

254: Partition board

255: Air intake

261, 262: Longitudinal holes

263, 264: Horizontal through hole

265: Ventilation slot

266:Piercing

267: Latch mounting hole

268: First vent

270: Second air hole

271: Vent

272: First connection hole

29: End cover

301: Intake seat

302: Air valve

303: Operating lever

304: First assembly thread

306: plane cutting

307: Curved surface

310: Rod mounting hole

311: Closed item

40: Latch

41: Connectors

411: Hat section

42: Pressure plate

43:Silencer

44: Silencer limiting plate

441: Via

45: Spring

Claims (8)

A pneumatic saw, which causes a saw blade to reciprocate when started, and the pneumatic saw comprises: a housing, which is hollow; a piston seat, which is arranged in the housing and forms a piston working space, and a plurality of return channels connected to the piston working space; a piston, which is arranged in the piston working space and is used to push the saw blade; and an air guide assembly, which is arranged in the housing, and the air guide assembly comprises a reversing brake block, an air guide seat, a partition plate arranged on a side of the air guide seat facing the piston seat, and an air blocking ring arranged on the air guide seat, the air guide seat having an air inlet in which the reversing brake block is arranged and connected to the piston working space, a plurality of main working air channels connected to the air inlet, and a plurality of main working air channels connected to the air inlet. and the secondary working air passages of the return passages, each of the primary working air passages and the secondary working air passages respectively comprises a longitudinal hole parallel to the air inlet passage, and a transverse through hole connecting the air inlet passage and the longitudinal hole, one end of the transverse through hole is shielded by the air blocking ring, the air blocking ring is fixed to the air guide seat by a latch, and the air guide seat has a latch mounting hole for the latch to be set. A pneumatic saw as described in claim 1, wherein the plurality of transverse through holes of the main working air channels are located on the same extension line, and two of the plurality of transverse through holes of the auxiliary working air channels are located on the same extension line. A pneumatic saw as described in claim 2, wherein two of the plurality of transverse through holes of the auxiliary working air passages are arranged in parallel. A pneumatic saw as described in any one of claims 1 to 3, wherein the air guide seat has a ventilation groove connecting the main working air passages and the air inlet passage. A pneumatic saw as described in claim 4, wherein the air guide seat has an air bleed hole connected to the air inlet duct, and the air bleed hole is not covered by the air blocking ring. A pneumatic saw as described in any one of claims 1 to 3, wherein the air guide seat has a plurality of first connecting holes, the piston seat has a plurality of second connecting holes respectively connected to the first connecting holes, each of the first connecting holes is provided with a connecting piece arranged therein, and the connecting piece has a cap portion that can limit the position of the air blocking ring. A pneumatic saw as described in any one of claims 1 to 3, wherein the pneumatic saw has an air intake assembly cooperating with the air guide assembly, the air intake assembly includes an air intake seat arranged in the housing, an air valve arranged in the air intake seat, and an operating rod arranged on the air intake seat and connectable to the air valve, the housing has a through hole for the operating rod to pass through, the air intake seat has an air inlet passage connected to the air intake passage of the air guide seat, an installation branch connected to the air inlet passage, and a rod installation hole corresponding to the through hole and provided for the operating rod to be inserted, the air valve is located at the meeting point of the air inlet passage and the installation branch, the opening of the installation branch is assembled with a sealing member, and the air intake seat and the housing are assembled by screwing. A pneumatic saw as described in claim 7, wherein the pneumatic saw includes an exhaust space formed between the air inlet seat and the shell, at least one silencer arranged in the exhaust space, at least one silencer limiting plate arranged on a side of the air inlet seat facing the air guide seat to limit the at least one silencer to be located at the periphery of the air inlet seat, and a spring respectively supporting the silencer limiting plate and the air guide seat, the silencer limiting plate having at least one through hole corresponding to the at least one silencer.

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