JP2009008039A - Air compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remove one factor causing noise by absorbing shock generated when compression pistons are turned reversely at top and bottom dead centers in a load transmission direction. <P>SOLUTION: In this air compressor, connecting rods 10, 11 are attached to a rotating shaft 3 rotatably provided in a crankcase 1 through a bearing 9, the compression pistons 12, 13 arranged at the end of the connecting rods 10, 11 are reciprocated in compression cylinders, and air introduced into the compression cylinders 14, 15 is compressed by the compression pistons 12, 13. The compression pistons are composed of a lower piston 18 integrated with the connecting rods 10, 11 and an upper piston 19 arranged above the lower piston. The lower piston 18 and upper piston 19 are fixed to each other through a sealing lip ring 27 and a shock absorbing material 28. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an air compressor provided with a compression piston cushioning structure that cushions an impact when a compression piston for compression of the air compressor reciprocates in a compression cylinder to reduce noise during operation.

  In general, in an air compressor that compresses air with a compression piston that reciprocates in a compression cylinder, when the compression piston reciprocates, the transmission direction of the load reverses at the top and bottom dead centers. At this time, the compression piston is swung in the opposite direction. The reciprocating inertia force of the compression piston mass is also reversed at the top and bottom dead centers. For this reason, an impact occurs between the connecting rod and the bearing or between the compression piston and the compression cylinder.

  For example, in a rocking piston type (reciprocating oscillation type) air compressor (see Patent Document 1), a slight gap is formed between the connecting rod and the bearing. Since the direction of movement of the bearing and the direction of movement of the connecting rod are different, when the connecting rod moves in the opposite direction, it strikes the bearing impactively. Since the connecting rod reverses at high speed, the impact becomes sound by vibration propagation.

  Moreover, in the air compressor (refer patent document 2) by which the compression piston is rotatably provided in the compression piston pin provided in the front-end | tip of a connecting rod, the guide liner is provided in the outer peripheral surface of the compression piston. . This guide liner guides the compression piston so that it moves along the compression cylinder, but there is a slight gap between the compression cylinder and the compression piston, so the connecting rod moves in the opposite direction at the top and bottom dead centers. When the upper and lower loads are switched, the compression piston is inclined. The diagonal compression pistons have two diagonal tip portions alternately contacting the inner surface of the compression cylinder, and noise such as cogging noise is generated by the impact at this time.

In this way, when an impact occurs between the connecting rod and the bearing or between the compression piston and the compression cylinder, this impact propagates to various parts of the compressor, and this vibration propagation becomes sound, which is one of the causes of noise. . Noise is not effective unless measures are taken for all the factors generated by the machine.
JP 2001-50159 A JP-A-8-254178

  The present invention solves the above-mentioned problems, and can eliminate one factor of noise by buffering the impact when the compression piston is at the top and bottom dead center and the load transmission direction is reversed. A buffer structure is provided.

  In other words, in order to solve the above-mentioned problem, the invention according to claim 1 is directed to a connecting shaft attached to a rotating shaft rotatably provided in a crankcase via an eccentric plate, and a compression piston provided at the tip of the connecting rod is used as a compression cylinder. In the air compressor that compresses air introduced into the compression cylinder by the compression piston, the compression piston is composed of a lower piston integral with the connecting rod and an upper piston disposed on the upper portion thereof. The lower piston and the upper piston are fixed via a sealing lip ring and a cushioning material.

According to a second aspect of the present invention, in the first aspect, the upper piston is disposed above the lower piston via the intermediate member, the sealing lip ring is fixed between the upper piston and the intermediate member, and the upper piston The cushioning material is fixed to the piston and the lower piston.

  The invention according to claim 3 is characterized in that, in claim 1 or 2, the upper piston is fixed to the lower piston by a headed bolt, and a cushioning material is interposed between the bolt head and the upper piston. To do.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, a concave portion is formed at the center of the lower piston, and a cylindrical portion that is inserted with play in the concave portion is formed at the central portion of the upper piston. In addition, a guide liner is attached between the concave portion and the cylindrical portion.

  According to the fifth aspect of the present invention, a connecting rod is attached to a rotating shaft rotatably provided in the crankcase via an eccentric plate, and a compression piston provided at the tip of the connecting rod is reciprocated in the compression cylinder. In the air compressor for compressing air introduced into the compression cylinder, the compression piston is rotatably provided at the end of the connecting rod, and the guide liner is provided on the outer peripheral surface of the compression piston and the outer periphery of the compression piston. A cushioning material is arranged at each of an upper portion and a lower portion between the inner peripheral surface of the first and second inner surfaces.

  According to a sixth aspect of the present invention, a connecting rod is attached to a rotating shaft provided rotatably in a crankcase via an eccentric plate, and a compression piston provided at the tip of the connecting rod is reciprocated in the compression cylinder. In the air compressor for compressing air introduced into the compression cylinder, the piston rod is divided into upper and lower parts and connected via a cushioning material.

  According to the first aspect of the present invention, the compression piston in the compression cylinder is constituted by the lower piston integral with the connecting rod and the upper piston disposed on the upper portion thereof, and the lower piston and the upper piston are connected to the sealing lip ring. Since the impact is generated when the compression piston reverses at the top and bottom dead centers, the impact energy corresponding to the mass of the upper piston in the entire compression piston is due to the cushioning material. As it is absorbed, the overall impact is mitigated. Accordingly, the generation of noise between the connecting rod and the inner bearing is reduced, and the sound during operation is quieter.

  According to the second aspect of the present invention, the compression piston is disposed on the upper part of the lower piston integral with the connecting rod via the intermediate member, and the sealing lip ring is fixed between the upper piston and the intermediate member. Since the upper piston and the lower piston are fixed via the cushioning material, the sealing lip ring and the cushioning material are separately fixed, so that they are firmly fixed, and the case of claim 1 Similarly, even if an impact occurs when the compression piston reverses at the top and bottom dead center, the impact energy corresponding to the mass of the upper piston is absorbed by the buffer material in the entire compression piston, so the entire impact is mitigated. Therefore, the generation of noise between the connecting rod and the inner bearing is reduced, and the sound during operation is quieter.

  According to the third aspect of the present invention, the upper piston is fixed to the lower piston by the headed bolt, and the shock absorber is interposed between the bolt head and the upper piston. Since it is not transmitted to the vehicle, the relaxation of the shock during operation is not impaired.

  According to the invention which concerns on Claim 4, while forming a recessed part in the center of a lower piston and forming the cylinder part inserted in the said recessed part with play in the center part of an upper piston, Since the guide liner is installed between them, the movement of the upper piston is always correctly guided by the guide liner.

  According to the invention which concerns on Claim 5, while providing a compression piston in the edge part of the said connecting rod so that rotation is possible, it is between the outer peripheral surface of a compression piston, and the inner peripheral surface of the guide liner provided in the outer periphery of the said compression piston. Since the cushioning material is placed at the upper and lower parts, when the compression piston reciprocates, it occurs between the guide liner of the compression piston and the compression cylinder when the load transmission direction is reversed at the top and bottom dead center. The impact is reduced by the buffer material. Accordingly, the generation of noise between the compression piston and the compression cylinder is reduced correspondingly, and the operation sound is quieter.

  In the invention according to claim 6 as well, even if an impact occurs when the compression piston reverses at the top and bottom dead center, the impact energy corresponding to the mass of the compression piston in the upper part divided in the entire compression piston is buffered. Since it is absorbed by the material, the overall impact is mitigated. Therefore, the generation of noise between the connecting rod and the inner bearing is reduced, and a quiet driving sound can be expected.

  The structure of the air compressor according to the present invention will be described with reference to FIG.

  The air compressor A of the present invention is a reciprocating type, and reference numeral 1 denotes a crankcase. An electric motor 2 and a rotating shaft 3 are accommodated in the crankcase 1, and a stator 4 composed of a stator coil and the like is provided to surround the rotor 5 from the outer peripheral side. The rotor 5 rotates the rotating shaft 3 by electromagnetic force acting between the stator 4 and is made of a permanent magnet or the like and is provided integrally with the rotating shaft 3. The rotating shaft 3 is rotatably supported by ball bearings 7 provided at the end wall of the crankcase 1 on the electric motor 2 side and the center of the case cap 6.

  Two eccentric plates 8 are fixed to the rotary shaft 3, and two connecting rods 10 and 11 are connected to each other via bearings 9. One connecting rod 10 is connected to the compression piston 12 of the primary compressor, and the other connecting rod is connected. 11 is connected to the compression piston 13 of the secondary compressor.

  The compression piston 12 of the primary compressor a1 is slidably accommodated in a cylindrical compression cylinder 14. The compression piston 13 of the secondary compressor a2 is slidably accommodated in a cylindrical compression cylinder 15. Then, air is introduced into the compression cylinder 14 of the primary compressor a1. That is, air is introduced into the crankcase 1 through an intake hole (not shown) formed in the case cap 6 of the crankcase 1 and further taken into the upper chamber of the compression cylinder 14 of the primary compressor a1. ing. The compression cylinder 15 of the secondary compressor a2 is configured to be supplied with primary pressure air discharged from the primary compressor a1, and the compressed air compressed by the secondary compressor a2 is supplied to an external air tank (not shown). It is supplied and stored.

  That is, when the electric motor 2 is operated, the rotary shaft 3 rotates, but the rotation is converted into a reciprocating motion by the eccentric plate 8 and the connecting rod 10 of the primary compressor a1, and the compression piston 12 reciprocates in the compression cylinder 14. When the compression piston 12 moves backward in the intake process, the space in the compression cylinder 14 suddenly expands, so that the inside becomes negative pressure and air is introduced into the compression cylinder 14. When the compression piston 12 moves forward in the compression process, the space in the crankcase 1 suddenly expands, so that air is taken into the crankcase 1 and the space in the compression cylinder 14 shrinks at the same time. Therefore, the discharge port 16 formed in the compression cylinder 14 is opened and the compressed air is discharged. Thereby, the air sent into the compression cylinder 14 is compressed in the compression cylinder 14 and discharged as primary pressure air. The primary pressure air is supplied to the compression cylinder 15 of the secondary compressor a2. The primary pressure air in the compression cylinder 15 is further compressed by the reciprocating compression piston 13 and discharged as secondary pressure air, and is pressurized and supplied to the air tank for storage.

  Next, the present invention mainly relates to the structure of the compression piston. One embodiment relates to the locking piston of the primary compressor a1, and the other embodiment relates to the normal compression piston of the secondary compressor a2. Therefore, it will be described individually below.

[Embodiment 1]
In FIG. 2, reference numeral 12 denotes the locking piston shown in FIG. 1, which is composed of a lower piston 18 integral with the connecting rod 10 and an upper piston 19 on the upper part thereof.

  A recess 20 is formed at the center of the upper surface of the lower piston 18, and a screw hole 29 is formed at the center of the recess 20.

  The upper piston 19 is a disk-like member having substantially the same outer diameter as the lower piston 18, but a concave portion 21 is formed at the upper center portion, and an inner cylinder portion 22 is formed below the central portion of the concave portion 21. Yes. A screw insertion hole 23 is formed at the center of the recess 20 and the inner cylinder portion 22.

  An intermediate member 24 is disposed below the upper piston 19. The intermediate member 24 is formed by projecting an outer cylindrical portion 26 downward from a central circular hole of a metal donut-shaped disk body having substantially the same outer diameter as the upper piston 19, and the outer cylindrical portion 26 has a lower piston. 18 is fitted into the inside of the recess 20 and is screwed onto the outside of the inner cylinder portion 22 of the upper piston 19.

  Next, the lower piston 18 and the upper piston 19 are fixed via a sealing lip ring 27 and a cushioning material 28. The lip ring 27 is a donut-shaped sealing member made of a flexible material.

  When attaching the intermediate member 24, the lip ring 27, and the cushioning material 28 between the upper piston 19 and the lower piston 18, the outer cylinder portion 26 of the intermediate member 24 is fitted to the outside of the inner cylinder portion 22 of the upper piston 19. Then, the lip ring 27 is sandwiched between the upper piston 19 and the intermediate member 24. Further, the guide liner 30 is fitted to the inner peripheral surface of the recess 20. In this state, the lower piston 18 and the intermediate member 24 are superposed on the upper piston 19, and the outer cylinder portion 26 of the intermediate member 24 is fitted into the recess 20 of the lower piston 18. When the upper piston 19 is superposed on the lower piston 18, a ring-shaped cushioning material 28 is preliminarily disposed on the upper surface of the lower piston 18. A ring-shaped cushioning material 32 is also disposed on the bottom upper surface of the recess 20. Therefore, the upper piston 19 is superposed on the lower piston 18 via the buffer material 28.

  Further, a fixing head bolt 33 is inserted through the screw insertion hole 23 of the recessed portion 21 of the upper piston 19 and screwed into the screw hole 29 at the center of the recessed portion 20 of the lower piston 18. A cushioning material 35 is disposed between the lower surface of the head 34 of the bolt 33 of the headed bolt 33 and the upper surface of the recessed portion 21 of the upper piston 19.

  A sealing material 36 is attached between the outer peripheral surface of the shaft portion of the headed bolt 33 and the inner peripheral surface of the inner cylinder portion 22 of the upper piston 19.

  According to the above configuration, the lip ring 27 is sandwiched and fixed between the upper piston 19 and the intermediate member 24 by the fixing head bolts 33 and protrudes in a skirt shape outside the outer peripheral surface of the upper piston 19. The seal between the compression cylinder is secured. When the rotary shaft 3 is rotated by the electric motor 2 or the like, the rotation of the eccentric plate 8 is converted into a linear motion of the connecting rod 10, and the compression piston 12 reciprocates in the compression cylinder 14. After being sucked in, it is compressed and sent out to the secondary compressor.

  Further, the lower piston 18 and the upper piston 19 fixed together with the intermediate member 24 are in a state of being separated via a buffer material 28. For this reason, when the compression piston is reciprocating, even if an impact occurs when the compression piston 12 is reversed at the top and bottom dead centers, the impact energy corresponding to the mass of the upper piston 19 in the entire compression piston 12 is buffered. Since it is absorbed by the material 28, the entire impact is mitigated. Accordingly, the generation of noise between the connecting rod 10 and the inner bearing 9 is reduced and the operation becomes quieter.

  When the compression piston 12 is reversed from the bottom dead center and switched to the top dead center, the upper piston 19 impacts the lower surface of the bolt head 34 of the headed bolt 33. Since the shock absorbing material 35 is provided between the lower surface of 34 and the upper surface of the upper piston 19, the impact is also reduced. Therefore, the cause of noise generation in this portion is also eliminated.

  In addition, the inner cylinder portion 22 of the upper piston 19 is inserted into the central recess 20 of the lower piston 18, and a guide liner 30 is attached between the recess 20 and the inner cylinder portion 22. The movement is always guided correctly by the guide liner 30. And since the sealing material 32 is attached between the outer cylinder part 26 and the recessed part 20 upper surface, the air compressed in the upper chamber of the compression cylinder 14 passes between the intermediate member 24 and the lower piston 18. Leakage into the lower chamber of the compression cylinder 14 can be reliably prevented.

  The number of fixing bolts 33 is not limited to one. FIG. 3 shows an example in which two fixing head bolts 33 are used as means for fixing the upper piston 19 to the lower piston 18.

  Further, as another form of the compression piston structure, instead of the compression piston, as shown in FIG. 4, the rod portions 10 a and 10 b of the connecting rod 10 may be divided into upper and lower parts and connected via a cushioning material 38. . Also in this case, even if an impact occurs when the compression piston 12 is reversed at the top and bottom dead center, the impact energy corresponding to the mass of the compression piston 12 in the upper part divided in the entire compression piston is absorbed by the buffer material 38. As it is absorbed, the overall impact is mitigated. Accordingly, the generation of noise between the connecting rods 10 and 11 and the bearing 9 inside thereof is reduced, and the operation sound is quieter.

[Embodiment 2]
In FIG. 5, reference numeral 13 denotes a compression piston of the secondary compressor a <b> 2 shown in FIG. 1, and this compression piston 13 is rotatably supported via a piston pin 40 provided at the upper end of the connecting rod 11. Thus, it is fitted in the compression cylinder 15 so as to be able to reciprocate.

  The compression piston 13 is formed in a bottomed cylindrical shape, and is rotatably supported by a piston pin 40 provided on a side wall portion.

  A piston ring 42 is attached to the upper end of the outer peripheral surface of the compression piston 13. A guide liner 43 is attached to the outer periphery of the outer peripheral surface. The guide liner 43 is a member for guiding the compression piston 13 so as not to tilt when the compression piston 13 reciprocates.

  Next, cushioning members 44 are disposed between the outer peripheral surface of the compression piston 13 and the upper and lower portions of the inner peripheral surface of the guide liner 43, respectively.

  According to the above-described compression piston configuration, when the compression piston 13 is reciprocating, the compression piston 13 is reversed at the top and bottom dead center, and when the top and bottom loads are switched, the compression piston 13 instantaneously moves as shown in FIG. Therefore, it is inclined in the opposite direction and is inclined with respect to the compression cylinder 15. When inclined, the tip portions of the two diagonal lines p and q of the cross section of the compression piston of the guide liner 43 alternately hit the inner surface of the compression cylinder 15 and an impact is generated. However, since the shock absorbing material 44 is disposed between the upper and lower portions of the outer peripheral surface of the compression piston 13 and the upper and lower portions of the inner peripheral surface of the guide liner 43, the shock is alleviated by the shock absorbing material 44. Accordingly, the generation of noise between the compression piston and the compression cylinder is reduced correspondingly, and the operation sound is quieter.

  In addition, since the portion where the guide liner 43 hits the compression cylinder 15 and generates an impact is limited to the upper and lower portions of the guide liner 43, it is not necessary to provide the buffer material 44 in the middle portion of the guide liner 43. Further, the outer peripheral surfaces of the intermediate portion of the guide liner 43 and the intermediate portion of the compression piston 13 may be protruded to contact the inner surface of the guide liner 43.

  In addition, this invention is not limited to the compression piston of a primary compressor and a secondary compressor. It can also be applied to air compressors equipped with either a locking piston or a normal compression piston compressor.

Sectional drawing of the compression piston structure of the air compressor which concerns on this invention Cross section of the compression piston part of the primary compressor Sectional drawing of the other form of the compression piston Sectional drawing of another form of the compression piston Sectional view of the compression piston part of the secondary compressor Schematic diagram of switching of the top and bottom dead centers of the compression piston

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crankcase 12, 13 Compression piston 18 Lower piston 19 Upper piston 27 Lip ring 24 Intermediate member 28 Buffer material

Claims (6)

A connecting rod is attached to a rotating shaft provided rotatably in the crankcase via an eccentric plate, and a compression piston provided at the tip of the connecting rod is reciprocated in the compression cylinder, and the air introduced into the compression cylinder by the compression piston. In the air compressor that compresses
The compression piston is composed of a lower piston integral with the connecting rod and an upper piston disposed on the upper part thereof, and the lower piston and the upper piston are fixed via a sealing lip ring and a cushioning material. And air compressor. The upper piston is arranged on the upper part of the lower piston via an intermediate member, the sealing lip ring is fixed between the upper piston and the intermediate member, and the cushioning material is fixed to the upper piston and the lower piston. The air compressor according to claim 1, wherein:   The air compressor according to claim 1 or 2, wherein the upper piston is fixed to the lower piston by a headed bolt, and a buffer material is interposed between the bolt head and the upper piston.   A concave portion is formed in the center of the lower piston, a cylindrical portion is formed in the central portion of the upper piston with play, and a guide liner is attached between the concave portion and the cylindrical portion. The air compressor according to any one of claims 1 to 3, wherein the air compressor is characterized. A connecting rod is attached to a crankshaft rotatably provided in the crankcase via an eccentric plate, and a compression piston provided at the tip of the connecting rod is reciprocated in the compression cylinder, and air introduced into the compression cylinder by the compression piston. In the air compressor that compresses
The compression piston is rotatably provided at the end of the connecting rod, and cushioning materials are provided at the upper and lower portions between the outer peripheral surface of the compression piston and the inner peripheral surface of the guide liner provided on the outer periphery of the compression piston. An air compressor characterized by being arranged. A connecting rod is attached to a rotating shaft provided rotatably in the crankcase via an eccentric plate, and a compression piston provided at the tip of the connecting rod is reciprocated in the compression cylinder, and the air introduced into the compression cylinder by the compression piston. In the air compressor that compresses
An air compressor characterized in that the piston rod is divided into upper and lower parts and connected via a cushioning material.

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