JPH1144289A - Reciprocation type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a pump efficiency by providing a working chamber receiving therein gas leaking from a pump chamber through the outer circumference of a pump piston in a pump crank cylinder body, and providing a relief valve opening when a pressure in the working chamber reaches a specified value or more. SOLUTION: A reciprocation piston type compressor C comprises a pump piston 25 slidably fitted in a cylinder hole 24 of a pump cylinder body 20, and a working chamber 37 and a piston hole are formed in the piston 25. A valve installing hole 71 and a relief hole 72 are formed in a side wall of the body 20, and an annular groove 77 communicating the hole 72 with the chamber 37 is formed on the inner circumferential surface of the body 20. A relief valve 75 and a valve spring 76 are housed in a valve housing 73 fitted to a communication pipe 55 in an airtight manner. When an inner pressure of the chamber 37 increases to a specified value or more, the valve 75 is opened to discharge an excessive pressure in the chamber 37 to the communication pipe 55.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor used, for example, for supercharging an internal combustion engine, and more particularly to a pump cylinder body having a cylinder bore and a pump cylinder head connected to an end of the pump cylinder body. And a pump piston defining a pump chamber between the pump cylinder head and the pump piston slidably fitted in the cylinder bore, and a pump crankshaft for reciprocatingly driving the pump piston. Regarding improvement.

[0002]

2. Description of the Related Art Conventionally, such a reciprocating compressor has been
For example, it is already known as disclosed in JP-A-7-109929.

[0003]

Heretofore, in such a reciprocating compressor, no consideration has been given to controlling the back pressure of the pump piston.

[0004] It is an object of the present invention to provide the reciprocating compressor in which the back pressure of the pump piston can be controlled to improve the pump efficiency.

[0005]

To achieve the above object, the present invention provides a pump cylinder body having a cylinder hole, a pump cylinder head connected to an end of the pump cylinder body, and a pump cylinder head. And a pump piston that slidably fits into a cylinder hole by defining a pump chamber between the pump piston and a pump crankshaft that reciprocates the pump piston. In addition, a connection part between the pump crankshaft and the pump piston is housed in a hermetically sealed manner, and a working chamber for receiving gas leaking from the pump chamber through the outer periphery of the pump piston is provided. The relief valve for opening the valve and releasing the excess pressure to the low pressure section is provided in the pump cylinder body.
The feature of.

According to this feature, the gas leaked from the pump chamber to the working chamber via the outer periphery of the pump piston causes the pressure in the sealed chamber to rise, so that the pressure when the pump chamber is pressurized and the pressure in the working chamber are reduced. Is reduced, and as a result, gas leakage to the working chamber is reduced, and pump efficiency can be increased. If the pressure in the working chamber rises above a specified value, the relief valve opens to release the excess pressure to the low pressure section, so that an excessive rise in the pressure in the working chamber can be prevented.

In a second aspect of the present invention, in addition to the above-described features, the low-pressure section is a suction system connected to a pump chamber.

According to this feature, the pressurized gas released from the working chamber by opening the relief valve is sucked into the pump chamber again from the suction system, so that it is not discharged to the outside and there is no waste.

[0009] In addition to the first or second feature, the present invention further comprises a first and second pump cylinder heads which define first and second pump chambers at both ends of a pump cylinder main body. First and second pump chambers, at opposite ends of a single pump piston, defining first and second pump chambers in cooperation with first and second pump cylinder heads.
A piston head is formed, a pump crankshaft is connected to a pump piston in a working chamber penetrating between the piston heads, and an annular groove communicating with the working chamber is provided on an inner peripheral surface of the pump cylinder body. A third feature is that the valve is connected to the relief valve.

According to this feature, two pump chambers can be formed in a single pump cylinder main body, and the discharge amount can be increased. Moreover, the pressure of the working chamber in the pump piston can be applied to the relief valve through the annular groove on the inner peripheral surface of the pump cylinder main body without being obstructed by the piston.

Further, in addition to the first or second feature, the present invention further comprises a first and second features provided at both ends of the pump cylinder body.
First and second pump cylinder heads defining a pump chamber are coupled, and the first and second pump cylinder heads are cooperated with the first and second pump cylinder heads at both ends of a single pump piston housed in the pump cylinder body. First and second piston heads defining a second pump chamber are formed, and a pump crankshaft supported on both side walls of the pump cylinder body is connected to the pump piston in a working chamber passing between the piston heads; A fourth feature is that a through hole is provided in the pump crankshaft from the shaft end to the working chamber, and the through hole is connected to a relief valve.

According to this feature, similarly to the above, two pump chambers can be formed in a single pump cylinder body,
The discharge amount can be increased. In addition, the pressure in the working chamber in the pump piston can act on the relief valve through the through hole of the pump crankshaft without being obstructed by the piston.

Still further, according to the present invention, in addition to the first, second, third or fourth features, a bearing hole is provided in a side wall of the pump cylinder body so that a pump crankshaft penetrates to connect to a driving source. A fifth feature is that a seal member capable of withstanding the valve opening pressure of the relief valve is mounted in the bearing hole.

According to this feature, it is possible to prevent the pressure in the working chamber from leaking from the bearing hole of the pump crankshaft before the relief valve is opened.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on embodiments of the present invention shown in the accompanying drawings.

1 to 3, reference numeral E denotes a motorcycle internal combustion engine provided with a reciprocating piston type compressor C of the present invention. The engine body 1 of the internal combustion engine E is configured by bolting a cylinder head 1b to an upper end surface of a cylinder block 1a, and the cylinder head 1b has a combustion chamber facing a head of a piston 2 housed in the cylinder block 1a. 3, an intake port 4, an exhaust port 5, and a supercharging port 6 connected to the combustion chamber 3, respectively.
Are formed. An intake valve 7, an exhaust valve 8 for opening and closing the intake port 4, the exhaust port 5, and the supercharging port 6, respectively.
And a supercharging valve 9, an ignition plug 10 for igniting the air-fuel mixture introduced into the combustion chamber 3, and a single valve operating camshaft 11 for opening and closing the three valves 7, 8, and 9. 1b. At this time, the supercharging valve 9 and the spark plug 10 are arranged in a V-shape in the axial direction of the valve operating camshaft 11, and the intake valve 7 and the exhaust valve 8 are perpendicular to the axis of the valve operating camshaft 11. Are arranged in such a manner as to be arranged in a V-shape in the direction in which they are formed. Each of the valves 7, 8, 9 is provided with a valve spring 12, 13, 14 for urging the valve in the closing direction.

The valve operating cam shaft 11 is supported by the cylinder head 1b via a pair of left and right ball bearings 15 and 16, and an intake cam 11i and an exhaust cam 11e are disposed between the bearings 15 and 16. The supercharging cam 11c is disposed at the right end of the bearing 16 projecting outward. A driven sprocket 18 driven via a chain 17 from a crankshaft (not shown) connected to the piston 2 is fixed to the protruding end of the valve camshaft 11 to the outside of the left bearing 15. Is done. The intake and exhaust cams 11i and 11e are connected to the intake and exhaust rocker arms 19, respectively.
The supercharging cam 11c has a tapered shape and is directly engaged with the supercharging valve 9 by engaging with the intake and exhaust valves 7, 8 via i, 19e.

When the valve camshaft 11 is driven from a crankshaft (not shown) via the chain 17, cams 11i, 11e, 11c for intake, exhaust and supercharging, and valve springs 12,
In cooperation with 13 and 14, the intake, exhaust and supercharging valves 7, 8, and 9 are opened and closed according to the timing shown in FIG.

The intake port 4 and the exhaust port 5 communicate with an intake manifold and an exhaust manifold (neither is shown) as in a general internal combustion engine, but the supercharging port 6 is connected to the supercharging cam 11c. It communicates with the discharge conduit 57 of the reciprocating piston type compressor C of the present invention disposed adjacent to the outer end.

4, 5 and 7, the reciprocating piston type compressor C has bearing bosses 21 on both left and right outer surfaces.
The pump cylinder body 20 includes a pump cylinder body 20 having a protruding portion 22, a pump piston 25 slidably fitted in a cylinder hole 24 of the pump cylinder body 20, and a pump crankshaft 26 for driving the pump piston 25. The pump cylinder body 20 has the left bearing boss 21 fitted in the mounting hole 27 in the right side wall of the cylinder head 1b, and is connected by bolts 28 (see FIG. 7).

The pump piston 25 does not have a piston ring, and has a cylinder bore 24 formed in the pump cylinder body 20.
It slides directly inside, and lubricating grease is applied to those sliding surfaces.

The bearing bosses 21 and 22 have bearing holes 21a and 22a reaching the inner surface of the pump cylinder body 20, respectively. And one end thereof is connected to the valve operating camshaft 11 via a spline 31. The left bearing hole 21
a, the pump crankshaft 26 outside the bearing 29
The oil seal 32 closely attached to the outer periphery of the oil seal is mounted. The oil seal 32 is configured as a high pressure type that can withstand a valve opening pressure of a relief valve 75 described later.

The bearing 30 is inserted into the right bearing hole 22a.
The seal plug 33 adjacent to the outer surface of the bearing boss is mounted, and a cap 34 covering the seal plug 33 is screwed to the outer periphery of the bearing boss 22.

The cylinder hole 24 of the pump cylinder body 20
Are closed by a pair of first and second pump cylinder heads 23 ₁ and 23 ₂ , and the first and second pump chambers 3 are located between the first and _second pump cylinder heads 23 ₁ and 23 _2.
6 _1, 36 first and second piston head defining ₂ 2
5 _1, 25 ₂ are formed at both ends of the pump piston 25.

The pump piston 25, between the two piston heads 25 _1, 25 _2, a circular working chamber 37 which penetrates deviate to the first piston head 25 ₂ side, a first piston head 25 ₁ in the transverse direction A piston pin hole 38 that penetrates and supports a piston pin 39 is formed, and the working chamber 37 has a crankpin 26 a of the pump crankshaft 26.
And the connecting rod 40 connecting the crank pin 26a to the piston pin 39 are accommodated.

The connecting rod 40 has a first bearing hole 40a at the end on the crank pin 26a side and a second bearing hole 40b at the end on the piston pin 39 side, and is mounted in these bearing holes 40a, 40b. The first and second needle bearings 41 and 42 support the crankpin 26a and the piston pin 39, respectively. In the first bearing hole 40a, a pair of left and right seal members 43, 43 which are in close contact with the outer peripheral surface of the crank pin 26a with the first needle bearing 41 interposed therebetween, are mounted. In the second bearing hole 40b,
The piston pin 39 sandwiches the second needle bearing 42
And a pair of left and right seal members 44, 44 which are in close contact with the outer peripheral surface of the cover.

In the connecting rod 40, an oil reservoir 46 is formed in the middle of the connecting rod 40 and is sealed by a cap 45. Oil holes 47 and 48 communicating the oil reservoir 46 with both bearing holes 40a and 40b are formed. Drilled. Grease for lubrication is sealed in the oil reservoir 46.

The pump piston 25 has a working chamber 37 and a piston pin hole 38 for facilitating the machining thereof.
The two piston halves 25a, 25b are divided between the two piston halves 25a, 25b.
Are joined by

As shown in FIGS. 4 to 6, the ₂ first and second pump cylinder heads 23 _1, 23, and the fitting hole 50 in the opposed surfaces of the pump cylinder body 20, respectively, annularly diameter than Are provided, and a cylindrical suction chamber 52 surrounded by the discharge chamber 51 is provided. Through bolt 53 and nut 5
With 4 the pump cylinder heads 23 ₁ and 23 ₂ are integrally connected to each other.

Further, both pump cylinder heads 23 ₁ , 23
The _2, a first communication pipe 55 ₁ communicating between them the suction chamber 52, a ₂ second communicating pipe 55 communicating between them in the discharge chamber 51, 51 is attached, further second pump cylinder head 23 the _2, an intake conduit 56 which communicates the suction chamber 52 to an intermediate portion of an intake manifold (not shown) of the internal combustion engine E, and a discharge conduit 57 which communicates the discharge chamber 51 to the supercharging port 6 of the internal combustion engine E Connected.

The fitting holes 50 are provided between the pump cylinder body 20 and the pump cylinder heads 23 ₁ and 23 _2.
, The valve device 58 is provided as follows.

That is, as shown in FIGS. 8 and 9, the valve device 58 is constituted by sequentially stacking an annular back plate 60, a thin intake valve plate 61, a valve seat plate 62, and a thin discharge valve plate 63. You.
Each of the constituent members 60, 61, 62, 63 is formed in a circular shape having an outer diameter substantially equal to the end of the pump cylinder body 20. And this valve device 58
The back plate 60 arranged on an end face side of the pump cylinder body 20 is fitted in the pump cylinder head 23 _1, 23 ₂ of the fitting hole 50 in the corresponding with the end of the pump cylinder body 20, the pump cylinder body 20 And between the pump cylinder heads 23 ₁ and 23 ₂ . As described above, the pinching force is applied to the first and second pumps while holding the pump cylinder body 20 with the through bolts 53 and the nuts 54.
Avidity binding between pump cylinder head 23 _1, 23 ₂ is its orゝuse.

At this time, each pump cylinder head 23 ₁ ,
23 ₂ , the first valve provided on the discharge valve plate 63 and the valve seat plate 62
First with knock pin 65 ₁ is fitted into the positioning hole 64 _1, the valve seat plate 62, the second knock pin ₆₅₂ is fitted in the second positioning hole 64 ₂ provided in the suction valve plate 61 and back plate 60 You.

In the valve seat plate 62, three sets of suction holes 67 are formed at intervals of 90 ° in the vicinity of the center thereof and three sets of suction holes 67 are formed in the vicinity thereof. Discharge hole 68
Are drilled at intervals of 180 °.

The suction valve plate 61 has four sets of suction holes 67.
, And two arc-shaped long holes 69 surrounding the two sets of discharge holes 68 so as not to close each other. Each suction reed valve 61a has a base end near the outer periphery of the suction valve plate 61 and a front end as close as possible to the center of the suction valve plate 61 as far as possible so as to extend in the radial direction of the suction valve plate 61. Along the suction valve plate 6
1 is formed by cutting a slit.

A notch-shaped restricting portion 60a corresponding to the base end of each of the suction reed valves 61a is provided on the inner periphery of the back plate 60. The restricting portion 60a restricts the bending fulcrum of the suction reed valve 61a. You. When the regulating portion 60a is formed in a cutout shape in this way, the bending length of the suction reed valve 61a can be made as long as possible without being obstructed by the opening edge of the cylinder hole 24 of the pump cylinder body 20. If the bending length is to be reduced, the restricting portion 60a may be formed in a convex shape.

The discharge valve plate 63 has two sets of discharge holes 68.
, And a large-diameter circular hole 70 surrounding the four sets of suction holes 67 so as not to be closed. The discharge reed valve 63a is formed by cutting a slit in the discharge valve plate 63 along its periphery.

The circular hole 7 is provided on the upper surface of the valve seat plate 62.
0 through the corresponding pump cylinder heads 23 ₁ ,
Annular partition wall 62a fitted to the inner circumference of the suction chamber 52 of 23 ₂
Is formed, whereby the suction chamber 52 and the discharge chamber 51 are partitioned.

As shown in FIG. 5, the pump cylinder body 2
0, a valve mounting hole 71 opening on the outer surface thereof,
A relief hole 72 penetrating the bottom wall of the valve mounting hole 71 is provided, and an annular groove 77 communicating the relief hole 72 with the working chamber 37 is formed on the inner peripheral surface of the pump cylinder body 20. The valve housing 73 is fitted airtightly on the outer circumference of the first communicating pipe 55 _1, the inside of the valve housing 73 first
Communicating pipe 55 through hole 74 communicating with the ₁ first communicating pipe 55 ₁
A plurality of holes are formed in the peripheral wall. The valve housing 73 includes a relief valve 75 capable of opening and closing the relief hole 72, and a valve spring 76 for urging the relief valve 75 in a closing direction by a specified set load.
And are accommodated.

In FIG. 4, reference numeral 80 denotes a suction chamber 52 provided in each of the pump cylinder heads 23 ₁ and 23 _2.
And is normally closed with a bolt 81.

Next, the operation of this embodiment will be described.

During operation of the internal combustion engine E, the valve operating camshaft 11
By the pump crank shaft 26 of the compressor C is driven, the pump piston 25 through a connecting rod 40 is provided to force the reciprocating, the vacuum in the first and second pump chambers 36 _1, 36 ₂ Accordingly Pressurization is alternately repeated.

[0043] During the first pump chamber 36 ₁ of the vacuum, and the closing of the discharge hole 68 by the discharge reed valve 63a suction reed valve 6
1a, the air in the intake manifold (not shown) of the internal combustion engine E is released by the suction conduit 56.
From the pump chamber 36 ₁ through the first communication pipe 55 ₁ , the suction chamber 52 and the suction hole 67 in this order. The pump chamber 3
6 The _first pressurized intake by suction reed valve 61a hole 6
By opening the discharge hole 68 by 7 closing the discharge reed valve 63a of the pump chamber 36 ₁ of the pressurized air discharge chamber through the discharge holes 68 51, second communicating pipe 55 _2, successively passed through by the internal combustion engine E to discharge conduit 57 To the supercharging port 6.

[0044] Also, when the second pump chamber 36 ₂ of the vacuum,
The first case of the pump chamber 36 ₁ and the same discharge reed valve 63a
By closing the opening of the suction reed valve 61a, the air in the intake manifold of an internal combustion engine E, intake from the conduit 56, without passing through the first connecting pipe 55 _1, the suction chamber 52, suction holes 67, the pump chamber It is drawn to the 36 _2. Also in the pressurization of the pump chamber 36 _2, the valve closing the discharge reed valve 63a of the first case of the pump chamber 36 ₁ and the same suction reed valve 61a
The valve opening, pressurized air of the pump chamber 36 ₂ is discharge hole 6
8 to the discharge chamber 51 from, and without a second communication pipe 55 ₂ is discharged to the discharge conduit 57, it is supplied to the supercharging port 6 of the internal combustion engine E.

On the other hand, in the internal combustion engine E, the intake valve 7 and the exhaust
With the timing shown in FIG.
It is opened and closed, in particular, the supercharging valve 9 is moved from the intake stroke to the compression stroke.
Over a period from just before the intake valve 7 closes to after it closes
The valve is opened only for a while. Thus, the supercharging valve 9
When the valve is closed, the first and second pump chambers 3 are closed as described above.
6 ₁, 36_TwoHigh pressure air supplied from the
The pressure is accumulated and the pressure is increased when the supercharging valve 9 is opened, that is, from the end of the intake stroke.
High pressure from the supercharging port 6 into the combustion chamber 3 during the early stage of the contraction stroke
Air is supercharged. As a result, the filling efficiency is increased,
The fuel engine E can exhibit high output.

Incidentally, in the compressor C, the first and second pump chambers 3 are formed by one pump piston 25.
Since 6 _1, 36 ₂ is operated alternately, to reduce the size of the pump piston 25 each part per total unit discharge amount,
It is possible to greatly reduce the size of the compressor C.

The pump crankshaft 26 has a pair of ball bearings 29 on both side walls of the pump cylinder body 20.
Since the pump crankshaft 26 is supported by the pump cylinder main body 20, the pump crankshaft 26 can be strongly supported by the highly rigid pump cylinder body 20.

Further, since the pump piston 25 is driven from the pump crankshaft 26 via the connecting rod 40, the piston pin 39 is rotated while the pump crankshaft 26 is rotating.
The change in the swing speed of the connecting rod 40 with respect to the piston pin 3 is smooth as shown in FIG.
The change in the rotation speed of the needle bearing 42 supporting the nozzle 9 is always smooth, and the durability thereof can be improved.

The pump piston 25 is provided with the cylinder hole 2 of the pump cylinder body 20 without the piston ring.
4, the power loss due to the sliding resistance can be reduced. However, since there is no piston ring, each pump chamber 36 ₁ , 36 ₂
Of the high pressure air leaks into the working chamber 37 through a minute gap between the pump piston 25 and the inner surface of the cylinder hole 24, but rather, the working chamber 3 is made use of this leak.
When the pressure in the first and second pump chambers 3 increases,
6 _1, 36 and the pressure of the _second pressurized, to reduce the difference between the pressure of the working chamber 37. As a result, the leakage amount of the gas into the working chamber 37 is reduced, it is possible to increase the operating efficiency of the pump chambers 36 _1, 36 _2.

If the internal pressure of the working chamber 37 rises above a specified pressure, the relief valve 75 is opened and the working chamber 37 is opened.
Is discharged to the low-pressure first communication pipe 55 ₁ ,
Excessive pressurization of the working chamber 37 is prevented, and the oil seal 32
The durability of the other seal portions can be improved, and the cylinder head 1 of the internal combustion engine E can be moved from the working chamber 37.
Gas leakage to b can be prevented. And the first
Gaseous discharged into the communicating pipe 55 _1, since we are again sucked into the first and second pump chambers 36 _1, 36 _2, without being released to the outside, there is no waste.

The first and second bearing holes 40a and 40b at both ends of the connecting rod 40 are connected to the crankpin 26a via the first and second needle bearings 41 and 42, respectively.
Since the needle bearings 41 and 42 have a relatively small diameter and a large load capacity, the connection strength between the pump crankshaft 26 and the pump piston 25 is high. Can withstand enough. In addition, both ends of the bearing holes 40a, 40b are sealed by a pair of sealing members 43, 43; 44, 44, and oil holes 47, 48 are formed in an oil reservoir 46 formed in an intermediate portion of the connecting rod 40. When the connecting rod 40 swings with the rotation of the pump crankshaft 26, the grease in the oil reservoir 46 is naturally supplied to the bearing holes 40a and 40b by the action of centrifugal force, and The bearings 41 and 42 can be lubricated to further increase their durability.

The back plate 60, the suction valve plate 61, the valve seat plate 62, and the discharge valve plate 63, which constitute the valve device 58, all have outer diameters substantially equal to the outer diameter of the end of the pump cylinder body 20. Since they were formed in a circular shape, they were
0 and corresponding pump cylinder heads 23 ₁ ,
Fitted to 23 ₂ of the fitting hole 50, the pump cylinder body 20 and the pump cylinder heads 23 ₁ can be sandwiched between 23 _2. Therefore, it is possible to it is possible to perform the assembling of the valve device 58 easily, covering it with the pump cylinder heads 23 _1, 23 _2, protected from contact with other object.

Further, in this case, the pumping cylinder body 20 of the through bolt 53 and the nut 54 and the first and second pump cylinder heads 2
3 _1, 23 because avidity for ₂ is its orゝuse a dedicated mounting member for the valve device 58 is not required,
This can contribute to simplification of the structure. In addition, the first knock pin 65 ₁ is fitted into the first positioning hole 64 ₁ provided in each of the pump cylinder heads 23 ₁ and 23 ₂ , the discharge valve plate 63 and the valve seat plate 62, and the valve seat plate 62 and the suction valve since the second positioning hole 64 ₂ provided in the plate 61 and back plate 60 fitted to the second knock pin _652, upon assembly of the valve device 58, the respective components pump cylinder head 23
_1, 23 ₂ easy to place around the axis, can be reliably held. Therefore, erroneous assembly of the valve device 58 can be prevented, and a proper valve action can always be ensured.

FIG. 12 shows another embodiment of the present invention, in which the right ball bearing 30 is directly pressed by a seal cap 34 'screwed to the right bearing boss 22 of the pump cylinder body 20, This seal cap 3
A relief hole 72 and a valve mounting hole 71 are provided in the end wall of 4 '. Also the seal cap 34 first communicating pipe 55 ₁ close to 'is arranged, the valve housing 73 attached thereto is fitted into the valve mounting hole 71. This valve housing 73 accommodates a relief valve 75 and a valve spring 76 as in the previous embodiment. The pump crankshaft 26 is provided with a through-hole 82 for communicating the working chamber 37 with the inside of the seal cap 34 '. The other configuration is the same as that of the previous embodiment. Therefore, in the drawing, the same reference numerals are given to portions corresponding to the previous embodiment, and the description thereof will be omitted.

Thus, also in this embodiment, the working chamber 3
7 through the relief hole 72 to the low-pressure first communication pipe 5.
It can be released to 5 _1.

The present invention is not limited to the above embodiments, and various design changes can be made without departing from the gist of the present invention. For example, a piston ring can be attached to the outer periphery of the pump piston 25. The first and second
One of the pump cylinder heads 23 ₁ and 23 ₂ is provided with a screw hole for screwing the tip of the through bolt 53 with the nut 54.
Can be provided in place of. In addition, compressor C
A single-acting piston type having only one pump cylinder head may be used.

[0057]

As described above, according to the first aspect of the present invention, the present invention provides a pump cylinder main body having a cylinder hole, a pump cylinder head coupled to an end of the pump cylinder main body, In a reciprocating compressor including a pump piston that slidably fits in a cylinder hole by defining a pump chamber between the pump cylinder head and a pump crankshaft that reciprocates the pump piston, a pump crank is provided. A connection part between the pump crankshaft and the pump piston is hermetically housed in the cylinder body, and a working chamber for receiving gas leaking from the pump chamber through the outer periphery of the pump piston is provided, and the pressure of the working chamber is regulated. When the pressure exceeds the value, a relief valve is opened in the pump cylinder body to open the valve and release excess pressure to the low pressure section. The leaked gas to the working chamber via the outer periphery of tons boosts the chamber, by reducing the difference between the pressure in the pressure and working chamber during pressurization of the pump chamber with,
Leakage of gas into the working chamber is reduced, and pump efficiency can be increased. If the pressure in the working chamber rises above a specified value, the relief valve opens to release the excess pressure to the low pressure section, so that an excessive rise in the pressure in the working chamber can be prevented.

According to the second feature of the present invention, since the low-pressure section is a suction system connected to the pump chamber, the pressurized gas released from the working chamber by opening the relief valve is discharged to the outside. And can be sucked into the pump chamber again from the suction system, so that there is no waste.

According to a third feature of the present invention, first and second pump cylinder heads defining first and second pump chambers are connected to both ends of the pump cylinder body, respectively, and housed in the pump cylinder body. Formed at both ends of a single pump piston are first and second piston heads which define first and second pump chambers in cooperation with the first and second pump cylinder heads. Since the pump crankshaft is connected to the pump piston in the working chamber passing therethrough, an annular groove communicating with the working chamber is provided on the inner peripheral surface of the pump cylinder body, and this annular groove is connected to the relief valve, so that a single Since two pump chambers can be formed in the pump cylinder main body, the discharge amount can be increased. Moreover,
The pressure in the working chamber in the pump piston can be applied to the relief valve through the annular groove on the inner peripheral surface of the pump cylinder body without being disturbed by the piston.

Further, according to a fourth feature of the present invention,
First and second pump cylinder heads defining first and second pump chambers are coupled to both ends of the pump cylinder body,
At both ends of a single pump piston housed in the pump cylinder body, first and second piston heads defining first and second pump chambers are formed in cooperation with the first and second pump cylinder heads. The pump crankshaft supported on both side walls of the pump cylinder body is connected to the pump piston in a working chamber penetrating between the piston heads, and the pump crankshaft is provided with a through hole communicating from the shaft end to the working chamber. Since this through-hole is connected to the relief valve, two pump chambers can be formed in a single pump cylinder body as described above, and the discharge amount can be increased, and the working chamber in the pump piston can be increased. Can be applied to the relief valve through the through hole of the pump crankshaft without being disturbed by the piston.

Further, according to a fifth aspect of the present invention,
Before the relief valve is opened, a side wall of the pump cylinder body is provided with a bearing hole through which the pump crankshaft is connected to the drive source, and a seal member capable of withstanding the opening pressure of the relief valve is installed in this bearing hole. Furthermore, it is possible to prevent the pressure in the working chamber from leaking from the bearing hole of the pump crankshaft.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a motorcycle internal combustion engine equipped with a backward-moving piston type compressor of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is an enlarged vertical sectional side view of the reciprocating piston type compressor in FIG.

FIG. 5 is a sectional view taken along line 5-5 of FIG. 4;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 5;

FIG. 7 is a view taken in the direction of arrow 7 in FIG. 4;

FIG. 8 is an exploded plan view of a main part of the compressor.

FIG. 9 is an exploded vertical sectional view of a main part of the compressor.

FIG. 10 is a diagram showing opening / closing timings of an intake valve, an exhaust valve, and a supercharging valve of the internal combustion engine, and operation timings of a pump piston of the compressor.

FIG. 11 is a diagram showing a change in rotation speed of a needle bearing on the pump piston side in the compressor.

FIG. 12 is a sectional view showing a modified example of the compressor around the relief valve.

[Explanation of symbols]

C · · · · reciprocating compressor 20 ... pump cylinder body 21a ... bearing holes 23 ₁ ... first pump cylinder head 23 ₂ ... second pump cylinder head 24 ... cylinder hole 25 ... pump Piston 25 ₁ ··· First piston head 25 ₂ ··· Second piston head 26 ··· Pump crankshaft 32 ··· Oil seal (seal member) 36 ₁ ··· First pump chamber 36 ₂ ··· Second pump chamber 52: suction chamber (low-pressure part, suction system) 55 _1. First communication pipe (low-pressure part, suction system) 75: relief valve 77: annular groove 82: through hole

Claims (5)

[Claims] 1. A pump cylinder body (20) having a cylinder hole (24), and the pump cylinder body (20).
Pump cylinder head (23 ₁ , 2
3 _2), the pump cylinder head (23 _1, 2
3 ₂ ), a pump chamber (36 ₁ , 36 ₂ ) is defined and a pump piston (25) slidably fitted in the cylinder hole (24), and the pump piston (25) is driven reciprocally. A reciprocating compressor provided with a pump crankshaft (26), wherein a connection between the pump crankshaft (26) and the pump piston (25) is housed in a pump crank cylinder body (20) in a sealed manner. , Pump room (36 ₁ , 3
A working chamber (37) for receiving gas leaking from 6 ₂ ) through the outer periphery of the pump piston (25) is provided, and when the pressure in the working chamber (37) exceeds a specified value, the valve is opened to reduce excess pressure to a low pressure section. (52, 55 ₁ ) relief valve (7
(5) A reciprocating compressor, wherein (5) is provided on a pump cylinder body (20). 2. The reciprocating compressor according to claim 1, wherein the low-pressure section is a suction system (55 ₁ , 52) connected to a pump chamber (36 ₁ , 36 ₂ ). 3. The pump cylinder body according to claim 1, wherein the first and second pumps are provided at both ends of the pump cylinder body.
Pump room (36₁, 36 _TwoFirst and second pons defining
Cylinder head (23₁, 23_Two) Combine and pump
Single pump fixie housed in cylinder body (20)
The first and second pump cylinder heads at both ends of the
C (23₁, 23_Two1) and 2nd pump chamber in cooperation with
(36₁, 36_Two) To the first and second pistons
(25₁, 25_Two) To form the two piston heads.
C (23₁, 23_Two) Between the working chamber (37)
The pump crankshaft (26) to the pump piston (2
5) an annular groove communicating with the working chamber (37);
(77) on the inner peripheral surface of the pump cylinder body (20).
Connecting the annular groove (77) to the relief valve (75).
Reciprocating compressor. 1 4. The pump cylinder according to claim 1, wherein said first and second pumps are provided at both ends of said pump cylinder body.
Pump room (36₁, 36 _TwoFirst and second pons defining
Cylinder head (23₁, 23_Two) Combine and pump
Single pump fixie housed in cylinder body (20)
The first and second pump cylinder heads at both ends of the
C (23₁, 23_Two1) and 2nd pump chamber in cooperation with
(36₁, 36_Two) To the first and second pistons
(25₁, 25_Two) Forming the pump cylinder body
Pump crankshaft (2) supported on both side walls of (20)
6) with both piston heads (23₁, 23_Two) Through
Working piston (25) in working chamber (37)
Connected to this pump crankshaft (26)
A through hole (82) communicating with the working chamber (37) is provided.
Characterized in that the hole (82) is connected to the relief valve (75)
Reciprocating compressor. 5. A bearing hole (21a) through which a pump crankshaft (26) penetrates through a side wall of a pump cylinder body (20) to connect to a drive source (E). ), And a seal member (32) capable of withstanding the opening pressure of the relief valve (75) is mounted in the bearing hole (21a).