JPH10103225A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compressor which is small-sized, can be installed on a vehicle, does not permit lube oil to get mixed in compressed air, maintains durability of the piston ring and cylinder even without lubrication and assures improvement of the capacity with a small size. SOLUTION: The captioned compressor is an air compressor in which a piston 20 reciprocates in a cylinder 1, and the piston 20 is coupled to a crankshaft 39 through a cross-slider crank mechanism and reciprocates in the cylinder 1. The interior of the cylinder 1 and that of a crankcase 25 are sealed by an oil seal 69 installed at the middle part of a piston rod 23. By the reciprocating motion of the piston 20, air is sucked into the cylinder through a suction port 3 formed in a cylinder head 2, compressed air is discharged through a discharge port 4, as well as air is sucked into the cylinder 1 through a suction port 70 of a valve-assembled body 26 secured to a bottomed cylinder 24 at the lower part of the cylinder 1, and compressed air is discharged through a discharge port 71 of a valve-assembled body 27 secured to the bottomed cylinder 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted air compressor.

[0002]

2. Description of the Related Art Compressed air is used as a driving source for various control mechanisms such as a brake system in a medium- to heavy-duty truck. At present, a reciprocating compressor that employs a general crank mechanism and supplies lubricating oil to a cylinder chamber to lubricate a piston ring and the like is used as the supply source.

[0003] If moisture is mixed with the compressed air, there is a danger of freezing in winter in the middle of the air piping. Therefore, it is necessary to separate compressed air and moisture. The current method of separating air and moisture is to absorb water in high-pressure air into a porous water absorbent and then rapidly reduce the pressure to release water from the water absorbent into the atmosphere. is there. This method has a disadvantage that the separation performance is reduced when lubricating oil is mixed with the compressed air.

When lubricating oil is mixed with compressed air, heat tends to carbonize the lubricating oil near the suction and discharge valves of the compressor. If sludge adheres to the discharge valve, the operation of the valve becomes imperfect, and the temperature of the compressed air increases more and more, so that carbonization is further promoted.

Therefore, it is desired that lubricating oil is not mixed with the compressed air.

[0006] Among general-purpose compressors, there are non-lubricated compressors. The most common type of this type uses a ball bearing for the crank part and a needle bearing for the piston and piston pin.These bearings are sealed with grease and lubricating oil enters the cylinder chamber. It is not to be.

[0007]

However, according to the above-described bearing structure, the size of the bearing portion becomes large, which is unsuitable for mounting on a vehicle.

On the other hand, some vacuum pumps drive a piston rod with a cam and perform an oil seal at the center of the piston rod. What has been put to practical use with this structure has a piston stroke as small as 20 mm or less, and cannot be used for compressors for medium and large trucks.

On the other hand, a cross slider crank mechanism is used in some machines. This includes a reciprocating rod, a slider frame fixed to the slider frame and supported reciprocally, a slider supported on the slider frame so as to be movable in a direction perpendicular to the direction of movement of the slider frame, and a slider. The crankshaft is rotatably connected. When this mechanism is connected to a piston, a piston in which side thrust does not act can be obtained, but there are no restrictions on the conditions to be established as compared with a normal crank mechanism, and there is no example used in a reciprocating compressor. Furthermore, there is no compressor that performs oil sealing at the intermediate portion of the piston rod.

[0010] It is an object of the present invention to be compact and can be mounted on a vehicle.
In addition, it is to prevent lubricating oil from being mixed into the compressed air. Another object of the present invention is to maintain the durability of the seal ring (piston ring) and the cylinder even without lubrication. Another object of the present invention is to increase the capacity with a small size.

[0011]

According to the present invention, in a compressor in which a piston reciprocates in a cylinder by a crank mechanism, the crank mechanism is constituted by a cross slider crank mechanism.

The cross slider crank mechanism includes a piston rod connected and fixed to a piston, a slider frame connected and fixed to the piston rod and supported so as to be able to reciprocate, and a cross direction perpendicular to the direction of movement of the slider frame. The slider includes a slider movably mounted in a window of the slider frame, and a crankshaft on which the slider is rotatably mounted.

Since the cross slider crank mechanism is employed as the crank mechanism for reciprocating the piston in the cylinder, the following operation is achieved.

[0014] The piston rod performs a pure sinusoidal linear motion without the higher order vibration components associated with conventional crank mechanisms. Therefore, generation of noise can be suppressed, and the durability of the seal ring (piston ring) and the cylinder mounted on the piston increases.

Since the piston rod performs a linear motion,
The oil seal can be easily performed in the middle of the piston rod. As a result, the interior of the cylinder and the interior of the crankcase can be easily sealed, and the interior of the cylinder can be easily maintained in a non-lubricating oil state.

Since the piston rod performs a linear motion and does not generate a piston slap, the durability of the seal ring (piston ring) mounted on the piston and the cylinder can be maintained even without lubrication.

Since the piston rod moves linearly and does not generate piston slap, generation of vibration and noise can be suppressed.

Since there is no relative movement between the piston and the piston rod, lubricating oil can be easily supplied to the inside of the piston through the inside of the piston rod, so that oil cooling of the piston can be easily performed.

Further, the compressor according to the present invention is characterized in that the compressor is provided with the following configuration in order to increase the capacity in a small size.

That is, the piston reciprocates in the cylinder by the crank mechanism, and in the downward stroke of the piston, air is sucked into the cylinder in which the upper surface of the piston faces from the suction port formed in the cylinder head, and the upward stroke of the piston In a compressor configured so that compressed air is discharged from a discharge port formed in a cylinder head, air is formed in the cylinder head in a rising stroke in a reciprocating stroke of the piston. Is drawn into a cylinder facing the lower surface of the piston from a suction port formed separately from the suction port, and compressed air is formed separately from a discharge port formed in the cylinder head during the downward stroke of the piston. Discharge port.

With the above configuration, two cycles per cycle
Since two suction and discharge strokes are obtained, the discharge amount increases.

The seal between the inside of the cylinder and the inside of the crankcase can be achieved by installing an oil seal in the middle of the piston rod. Lubricating oil can be prevented from being mixed into the air.

[0023]

1 to 5 show an embodiment of the present invention. FIG. 1 is a partially sectional front view of a compressor, and FIG.
Is a right side view in partial cross section showing a part of the compressor, (b) is a plan view of a slider, FIG. 3 is a plan view in partial cross section showing a crankcase part, and FIG. (A) is a bottom view showing a valve assembly to which a valve is attached, (b) is a longitudinal sectional view showing a suction valve portion in a compressor, and (c) is an attachment to the valve assembly. FIG. 5 shows a suction valve and a discharge valve on the opposite side of the cylinder head, and FIG.
(A) is a cross-sectional view showing a suction valve portion in the compressor,
(B) is a transverse sectional view showing a portion of a discharge valve in the compressor.

The compressor of the present invention is an air compressor in which a piston reciprocates in a cylinder. A cylinder head 2 is fixed to the upper surface of the cylinder 1.
Are provided with an air inlet 3 and a compressed air outlet 4.

The cylinder head 2 comprises a valve assembly 5 and a head body 6. The valve assembly 5 fixed to the upper surface of the cylinder 1 has a substantially square, flat plate shape, and has mounting holes 5a at four corners. A pair of discharge holes 7 are formed near the center of the valve assembly 5 in parallel with one end, and four suction holes 8 are arranged near one end. They are arranged in an arc along the direction.

A suction valve 9 is disposed on the lower surface of the valve assembly 5. The suction valve 9 is formed by a thin reed valve,
It has a ring shape, a part of which closes four suction holes 8, and two discharge holes 7 are arranged in the ring shape. Then, a catch 10 is placed on the base end of the suction valve 9, and the suction valve 9 is fixed to the valve assembly 5 with a set screw 11.

The discharge valve 1 is provided on the upper surface of the valve assembly 5.
2 are arranged. The discharge valve 12 is formed by a thin plate-shaped reed valve, and has an elongated rectangular shape.
Is closed. A discharge valve receiver 13 made of a plate having the same shape as the discharge valve 12 as viewed from above is disposed above the discharge valve 12, and both ends of the discharge valve 12 and the discharge valve receiver 13 are bolted to the valve assembly. 5 is fixed. The discharge valve receiver 13 has an arch shape that is curved upward. When the discharge valve 12 is opened, the discharge valve 12 curves upward and abuts on the lower surface of the discharge valve receiver 13 to regulate the lift amount. .

On the upper end surface of the cylinder 1, there is formed a notch 15 which is open to the inner periphery over the entire circumference, and the suction valve 9 is arranged in this notch 15. When the suction valve 9 is opened, the suction valve 9 bends downward, and the tip of the suction valve 9 abuts against the bottom surface of the cutout 15 (constituting the suction valve receiver), whereby the lift amount is regulated.

Inside the head body 6 fixed to the upper surface of the valve assembly 5, a space 16 in which the discharge valve 12 and the discharge valve receiver 13 are accommodated, and the space 16 to the discharge port 4
And a suction passage 18 communicating from the suction hole 8 to the suction port 3.
Are formed.

A piston 20 is inserted into the cylinder 1, and piston rings 21 and 22 are respectively mounted in two ring grooves formed on the outer peripheral surface of the piston 20, and a seal with the inner wall 1 a of the cylinder 1 is provided. I do. One end of a piston rod 23 is fixed to the center of the bottom surface of the piston 20, and the piston 20 is configured to reciprocate in the cylinder 1 by a cross slider crank mechanism.

The cylinder 1 has a lower end fitted and supported in a bottomed cylinder 24, and the bottomed cylinder 24 is fixed to an upper surface of a crankcase 25. In addition to forming the cylinder 1 from cast iron, the overall weight can be reduced and heat transfer can be improved by casting a cast iron sleeve with aluminum.

In the compressor according to the present invention, the suction / discharge mechanism is formed on the side opposite to the cylinder head 2 in addition to being formed on the cylinder head 2 side.

The outer shape of the bottomed cylinder 24 has a substantially square shape, and the valve assembly 26 of the suction valve is provided on the outer surface at the bottom.
And the valve assembly 27 of the discharge valve are fixed. The respective valve assemblies 26 and 27 are located on opposite sides of the outer peripheral surface of the bottomed cylinder 24.

The valve assembly 26 having a suction valve has a flat plate shape, two suction holes 28 are formed side by side, and a suction valve 29 is arranged on the inner surface. The suction valve 29 is formed of a thin plate-shaped reed valve, has an elongated rectangular shape, closes the two suction holes 28, and has both ends fixed to the valve assembly 26 with bolts 30.

On the other hand, a concave portion 32 is formed on the outer surface of the bottom of the bottomed cylinder 24, and the suction valve 29 is disposed in the concave portion 32. Further, two suction passages 33 penetrating from the inside of the cylinder 1 to the bottom surface of the concave portion 32 are formed at the bottom of the bottomed cylinder 24. doing. When the suction valve 29 is opened, the lift amount is regulated by bending the suction valve 29 inward and coming into contact with the bottom surface of the concave portion 32 (constituting the suction valve receiver).

The valve assembly 27 having a discharge valve also has a flat plate shape, two discharge holes 34 are formed side by side, and a discharge valve 35 is disposed on the outer surface. Discharge valve 3
Reference numeral 5 is formed of a thin plate-shaped reed valve, has an elongated rectangular shape, and closes the two discharge holes 34. Discharge valve 35
A discharge valve receiver 36 made of a plate material having the same shape as the discharge valve 35 as viewed from the outside is disposed outside of the valve assembly.
It is fixed to. The discharge valve receiver 36 has an outwardly curved arch shape, and when the discharge valve 35 is open, the discharge valve 3
5 is curved outward and abuts against the inner surface of the discharge valve receiver 36 to regulate the lift amount. On the other hand, the bottomed cylinder 24
The discharge hole 34 of the valve assembly 27 and the cylinder 1
Two discharge passages 38 communicating with the inside are formed.

It is desirable to provide a cooling water passage for cooling the suction passage 33 and the discharge passage 38 inside the bottomed cylinder 24.

A crankshaft 39 is disposed in the crankcase 25 in a direction perpendicular to the direction of movement of the piston 20 (hereinafter, referred to as a vertical direction), and both ends are rotatably supported by bearings 40. Crankshaft 3
Reference numeral 9 has one end protruding outward from the crankcase 25 and is configured to be rotationally driven by a driving source (not shown).

The crankshaft 39 is connected to the crankcase 2
5 has a pair of crank arms 41, and a slider 43 is rotatably attached to a crank pin 42 connected between the pair of crank arms 41.
The slider 43 is a block having a substantially square shape as viewed in the direction of the crankshaft 39, and is divided into upper and lower portions. A metal 44 is fixed to the inner periphery of a pin hole formed in the center portion. It is rotatably assembled.

A slider frame 45 is arranged around the slider 43. The slider frame 45 is a rectangular frame that is horizontally long when viewed in the direction of the crankshaft 39. The height of the horizontally long rectangular window hole 46 is substantially the same as the height of the slider 43, and the width is longer than the width of the slider 43. It has dimensions. The window hole 46 of the slider frame 45
Slider 43 attached to the crank pin 42
Are slidably mounted in the window hole 46 in a direction perpendicular to the direction of movement of the piston 20 (hereinafter referred to as a left-right direction).

The surface of the slider frame 45 that slides with the slider 43, that is, the upper and lower surfaces of the slider frame 45 where the window holes 46 are formed, are covered with porous Cr plating 47. It is desirable to improve the smoothness, surface roughness, and pore ratio of the surface of the Cr plating 47 after the Cr plating by surface processing. The slider 43 is formed of a cast iron material such as gray cast iron.

The slider frame 45 is mounted on the crankcase 2
5, a pair of guide rods 48, 4 so as to be able to reciprocate up and down
9 supported. A pair of guide rods 48, 49
Extends vertically in the crankcase 25 and is fixed to the crankcase 25, and passes through guide rod insertion holes 50 and 51 formed vertically in both ends of the slider frame 45 in the longitudinal direction. . The slider frame 45 has bushings 52, 53 mounted on upper and lower ends of a pair of guide rod insertion holes 50, 51, respectively. The bushings 52, 53 slidably support the guide rods 48, 49. doing.

The piston rod 23, which is fixed to the bottom of the piston 20 and extends downward, passes through the through holes 54, 55 formed from the lower end of the cylinder 1 to the bottom of the bottomed cylinder 24 and the upper surface of the crankcase 25. And crankcase 2
5 is connected and fixed to the center of the upper surface of the slider frame 45.

Next, lubrication of the cross slider crank mechanism and cooling of the piston will be described.

The lubricating oil supplied from the oil supply port 56 of the crankcase 25 into the compressor is supplied to an oil supply passage 57 formed inside one of the guide rods 48 and one of the guide rods 48.
Then, while sequentially passing through an oil supply passage 58 formed between the slider frame 45 and the guide rod insertion hole 50, while lubricating the sliding portion between one guide rod 48 and the bush 52, the slider frame 45
Is formed so as to flow into an oil supply path 59 formed at the bottom.

The lubricating oil that has flowed into the oil supply passage 59 of the slider frame 45 branches on the way to the other guide rod 49 side and the piston rod 23 side. The lubricating oil that has flowed to the other guide rod 49 side is supplied to an oil supply passage 60 formed between the guide rod 49 and the guide rod insertion hole 51.
After lubricating the sliding portion between the guide rod 49 and the bush 53, it falls into the crankcase 25 from the upper and lower ends.

The lubricating oil flowing to the piston rod 23 side is
After flowing into an oil supply path 61 formed in the piston rod 23 and entering a cooling chamber formed inside the piston 20 and cooling the piston 20 from the inside, an oil discharge path formed in the piston rod 23 It is configured to pass through 62 and be discharged into the crankcase 25 from the opening at the lower end.

The lubricating oil supplied from an oil supply port 63 opened on the side surface of the crankcase 25 to an oil supply passage 64 formed inside the crankshaft 39 is
It passes through the inside of the crankshaft 39 to reach the crankpin 42. The metal 44 has an annular groove formed in the inner periphery and an oil hole 65 formed in the slider 43 from the bottom of the annular groove.
The lubricating oil reaching the crank pin 42 is supplied to the sliding surface between the crank pin 42 and the metal 44, and a part of the oil is supplied to the slider 44. The oil flows into the oil groove 67 formed on the surface of the slider 43 through the oil hole 65 of the slider 43, and is supplied to the sliding surface between the slider 43 and the slider frame 45.

As described above, the lubrication and cooling oil passages are formed in the cross slider crank mechanism.

However, the interior of the cylinder 1 is in a non-lubricating oil state. That is, the bottomed cylinder 2 below the cylinder 1
An oil seal 69 is attached to an annular concave portion 68 formed on the inner surface of the bottom at the periphery of the through hole 54 of No. 4, and the inner periphery of the oil seal 69 is brought into contact with the outer periphery of the piston rod 23 to seal it. Lubricating oil is prevented from being supplied into the cylinder 1. Therefore, the piston rings 21 and 22 slide on the cylinder inner wall 1a without lubrication.

The operation will be described below. When the crankshaft 39 is rotated by a drive source (not shown), the slider 43 mounted on the crankpin 42 moves along a circular orbit around the center of the crankshaft 39. At this time, as the slider 43 moves in a circular orbit, the slider 43 slides in the window hole 46 of the slider frame 45, and accordingly, the slider frame 45 moves in a vertical direction (movement direction of the piston 20) by a sine. Perform a linear motion.

When the slider frame 45 makes a linear motion in the vertical direction as described above, the piston 2 moves through the piston rod 23 connected and fixed to the slider frame 45.
0 reciprocates in the cylinder 1.

When the piston 20 descends, the suction valve 9 opens. In other words, the suction valve 9 bends downward, and its tip contacts the bottom surface (suction valve receiver) of the notch 15 formed on the upper surface of the cylinder 1.

When the suction valve 9 is opened, air is released from the cylinder head 2.
Is sucked into the cylinder 1 from the suction port 3 through the suction hole 8, and the air is compressed by the rise of the piston 20.

When the air is compressed by the rise of the piston 20, the discharge valve 12 is opened at a predetermined compression position. That is, the discharge valve 12 curves upward and contacts the discharge valve receiver 13.

When the discharge valve 12 is opened, the compressed air is discharged from the discharge hole 7.
Through the discharge port 4 of the cylinder head 2.

On the other hand, when the piston 20 rises during the upward stroke of the piston 20, the suction valve 29 provided at a position opposite to the cylinder head 2 opens. That is, the suction valve 29 curves inward and abuts on the bottom surface of the recess 32 (suction valve receiver) on the outer surface of the bottomed cylinder 24.

The suction valve 29 is opened, and air is sucked into the cylinder 1 from the suction port 70 on the side opposite to the cylinder head 2 through the suction hole 28 and the suction passage 33.

When the piston 20 descends during the downward stroke of the piston 20, at a predetermined compression position,
The discharge valve 35 provided at a position opposite to the cylinder head 2 opens. That is, the discharge valve 35 curves outward and comes into contact with the discharge valve receiver 36.

When the discharge valve 35 is opened, the compressed air is discharged from the discharge port 71 on the opposite side of the cylinder head 2 through the discharge passage 38 and the discharge hole 34.

As described above, since the suction / discharge process is performed twice in one cycle, the discharge amount can be increased.

In addition, since the piston rod 23 driven by the rotation of the crankshaft 39 performs a linear motion with a pure sine by the cross slider crank mechanism, there is no higher-order vibration component associated with the conventional crank mechanism. Therefore, generation of noise can be suppressed, and the durability of the piston rings 21 and 22 and the cylinder 1 also increases. Further, since no piston slap is generated, the durability of the piston rings 21 and 22 and the cylinder 1 can be maintained even without lubrication. Further, since no piston slap is generated, generation of vibration and noise can be suppressed. Further, since there is no relative movement between the piston 20 and the piston rod 23, lubricating oil can be easily supplied to the inside of the piston 20 through the inside of the piston rod 23, so that oil cooling of the piston 20 can be easily performed.

[0063]

As described above, the compressor of the present invention can be made compact and can be mounted on a vehicle, and can prevent lubricating oil from being mixed into compressed air. Even without lubrication, the durability of the seal ring (piston ring) mounted on the piston and the cylinder can be maintained. Further, generation of vibration and noise can be suppressed. Further, the size can be increased and the capacity can be increased.

[Brief description of the drawings]

FIG. 1 shows one embodiment of the present invention, and is a partial cross-sectional front view of a compressor.

2A is a right side view, partly in cross section, showing a part of the compressor, and FIG. 2B is a plan view of a slider.

FIG. 3 is a partially sectional plan view showing a crankcase portion.

4A and 4B show a suction valve and a discharge valve on a cylinder head side, wherein FIG. 4A is a bottom view showing a valve assembly to which the valve is attached, and FIG. FIG. 3C is a longitudinal sectional view showing a portion of the discharge valve attached to the valve assembly.

5A and 5B show a suction valve and a discharge valve on the side opposite to the cylinder head, wherein FIG. 5A is a cross-sectional view showing a part of a suction valve in a compressor, and FIG. FIG.

[Explanation of symbols]

 Reference Signs List 1 cylinder 1a cylinder inner wall 2 cylinder head 3, 70 suction port 4, 71 discharge port 5, 26, 27 valve assembly 5a mounting hole 6 head body 7, 34 discharge hole 8, 28 suction hole 9, 29 suction valve 10 stop Gold 11 Set screw 12, 35 Discharge valve 13, 36 Discharge valve receiver 14, 30, 37 Bolt 15 Notch 16 Space 17, 38 Discharge passage 18, 33 Suction passage 20 Piston 21, 22 Piston ring 23 Piston rod 24 With bottom Cylinder 25 Crank case 32 Concave part 39 Crank shaft 40 Bearing 41 Crank arm 42 Crank pin 43 Slider 44 Metal 45 Slider frame 46 Window hole 47 Cr plating 48, 49 Guide rod 50, 51 Guide rod insertion hole 52, 53 Guide bush 54, 55 Through holes 56, 63 Oil supply port 5 , 58,59,60,61,64,66 oil supply passage 62 the oil discharge passage 65 the oil hole 67 the oil groove 68 annular recess 69 oil seal

Claims (2)

[Claims] 1. A piston reciprocates in a cylinder by a crank mechanism, and in a descending stroke of the piston, air is sucked from a suction port formed in a cylinder head into a cylinder in which an upper surface of the piston faces, and an upward stroke of the piston In the compressor, the compressed air is discharged from a discharge port formed in the cylinder head, wherein the crank mechanism is connected to a piston rod fixedly connected to a piston, and connected to the piston rod. A slider frame that is fixed and reciprocally supported, a slider that is mounted in a window hole of the slider frame so as to be movable in a direction perpendicular to the direction of movement of the slider frame, and a slider that is rotatably mounted. A cross-slider crank mechanism comprising: In the ascending stroke, air is sucked from a suction port formed separately from the suction port formed in the cylinder head into the cylinder where the lower surface of the piston faces, and in the descending stroke of the piston, compressed air is compressed. A compressor configured to be discharged from a discharge port formed separately from a discharge port formed in a cylinder head. 2. The compressor according to claim 1, wherein the inside of the cylinder and the inside of the crankcase are sealed by an oil seal attached to an intermediate portion of the piston rod.