JPH0628276U - Air compressor - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent the load on the drive engine during unloading without impairing the durability of the components. [Structure] The inside of the cylinder part 1 and the suction port 23 are provided with an opening 2
6. Communicate through the open passage 27. This open passage 2
An opening / closing valve 29 including a valve plate 36 and a protrusion 33 is provided in the middle of 7. The on-off valve 29 opens in association with the feeding of compressed air into the unload cylinder 30 to open the cylinder portion 1 to the atmosphere.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The air compressor according to the present invention is incorporated into an air brake device for a large vehicle, for example, and is used to create compressed air for braking.

[0002]

[Prior art]

 BACKGROUND ART As a braking device for large vehicles such as large trucks and buses, air brake devices that generate braking force by the force of compressed air are widely used. In such an air brake device, the compressed air created by driving the air compressor by the running engine of the above-mentioned large vehicle is stored in the air tank, and during braking, the force of the compressed air discharged from this air tank causes the friction material. On the inner surface of the drum and both sides of the disc.

The air compressor includes a cylinder part whose one end is closed by a partition wall, and a piston driven by the traveling engine to reciprocate in the cylinder part and move an end face of the partition wall into a distance. , A suction hole and a discharge hole formed in the partition wall, respectively, and a suction valve provided in the suction hole portion, which is opened only when the end face of the piston moves away from the partition wall, and the piston provided in the discharge hole portion. It is composed of a discharge valve that opens only when the end face of is close to the partition wall.

The air compressor configured as described above compresses the air sucked into the cylinder portion through the suction hole as the piston reciprocates, and sends the compressed air toward the air tank through the discharge hole. That is, compressed air is discharged from this discharge hole and sent to the air tank through a discharge valve which is a check valve.

By the way, the piston is constantly reciprocating when the traveling engine is rotating, whereas when the compressed air is sufficiently stored in the air tank, the discharge is Not only is it unnecessary to send out compressed air from the holes, but the power of the running engine is wasted, resulting in poor running performance of the vehicle and poor fuel efficiency.

Therefore, conventionally, when a sufficient amount of compressed air is stored in the air tank, the inside of the cylinder is opened to the atmosphere and the force required for the reciprocating movement of the piston is made extremely small. A so-called unloading mechanism that prevents the power of the running engine from being wasted is attached to the air compressor as described above.

For example, FIG. 2 shows an unloading mechanism described in Japanese Utility Model Publication No. 2-10317. This unload mechanism keeps the suction hole open when a sufficient amount of compressed air is stored in the air tank. For this reason, the unload cylinder 4 is provided so as to face the suction hole 3 provided in the partition wall 2 in which one end of the cylinder portion 1 is closed.

When a sufficient amount of compressed air is stored in the air tank, the compressed air is sent into the unload cylinder 4 to lower the unload piston 5 in FIG. The reed 7 (leaf spring) forming the suction valve is pressed. As a result, regardless of the pressure in the cylinder portion 1, the intake valve remains open, the inside of the cylinder portion 1 communicates with the atmosphere, and the piston 8 fitted in the cylinder portion 1 is connected. The reciprocating movement of can be done with a light force.

Further, FIG. 3 shows an unloading mechanism described in Japanese Utility Model Publication No. 32875/1990. This unload mechanism keeps the suction hole and the discharge hole closed when a sufficient amount of compressed air is stored in the air tank. Therefore, the unload cylinders 12 and 13 are provided so as to face the suction passage 9 communicating with the suction hole 3 provided in the partition wall 2 and the discharge passage 11 communicating with the discharge hole 10.

When a sufficient amount of compressed air is stored in the air tank, the compressed air is sent into the unload cylinders 12 and 13 to lower the unload pistons 14 and 15 in FIG. The suction passage 9 and the discharge passage 11 are closed by the valve bodies 16 and 17. As a result, the inside of the cylinder portion 1 is cut off from the outside.

When the piston 8 reciprocates in the cylinder 1, air is compressed in the cylinder portion 1 when the piston 8 approaches the partition wall 2, so power is consumed to move the piston 8. However, when the piston 8 moves away from the partition wall 2, the compressed air existing in the cylinder portion 1 pushes the piston 8, so that power is sent from the air compressor side to the engine.

[0012]

[Problems to be solved by the device]

 However, the conventional air compressor incorporating the unloading mechanism configured as described above has the following problems.

First, in the case of the structure of the first example shown in FIG. 2, since the lead 7 is pressed by the tip portion of the rod 6 during unloading, the lead 7 is easily damaged. That is, when the piston 8 is approaching the partition wall 2 and the reed 7 is pressed against the partition wall 2, when compressed air is sent into the unload cylinder 4, the tip of the rod 6 and the reel 6 are released. A strong force acts on the lead 7 and a large load acts on the lead 7, and the durability of the lead 7 is impaired.

Further, in the case of the structure of the second example shown in FIG. 3, since the pressure fluctuation in the cylinder portion 1 is large, the operation of the traveling engine that drives the air compressor is likely to be unstable. Further, depending on the operation timing of the unload cylinders 12 and 13, the inside of the cylinder part 1 may become negative pressure as the piston 8 moves. However, when the inside of the cylinder part 1 becomes negative pressure, the displacement of the air compressor Lubricating oil for lubricating the parts is easily sucked into the space 18 between the inner surface of the partition wall 2 and the end surface 8a of the piston 8.

The lubricating oil sucked into the space 18 may be sent into the air tank as the pressure in the air tank drops and sent to the brake device, which may adversely affect the brake device. , Again not desirable.

The air compressor of the present invention eliminates any of the above inconveniences.

[0017]

[Means for Solving the Problems]

 The air compressor of the present invention, like the conventional air compressor described above, reciprocates within the cylinder part, one end of which is closed by the partition wall, and the end face of the air compressor is moved toward and away from the partition wall. A piston to be moved, a suction hole and a discharge hole respectively formed in the partition wall, a suction valve which is provided in the suction hole portion, and which is opened only when the end face of the piston moves away from the partition wall, and a discharge hole portion. A discharge valve that opens only when the end surface of the piston approaches the partition wall, a suction port that communicates with the suction hole, and a head that has a discharge port that communicates with the discharge hole and that is provided above the partition wall. I have it.

Particularly, in the air compressor of the present invention, an opening hole is provided in a part of the partition wall and has one end opened to the cylinder portion, the other end of the opening hole and the suction port. And an opening / closing valve provided in the middle of the opening passage, and a drive device for opening / closing the opening / closing valve.

[0019]

[Action]

 In the case of the air compressor of the present invention configured as described above, when it is not necessary to send out compressed air, the drive device opens the on-off valve and opens the cylinder part through the open hole, the open passage, and the suction port. Open to the atmosphere.

As a result, even when the piston approaches the partition wall, air is not compressed, and the piston can be moved with a light force.

[0021]

Embodiment FIG. 1 shows an embodiment of the present invention. A piston 8 is reciprocally fitted in a cylinder portion 1 of which one end is closed by a partition wall 2. The piston 8 is driven by a vehicle running engine, and its end face 8a moves toward and away from the partition wall 2.

A suction hole 3 and a discharge hole 10 are formed in the partition wall 2. A head 19 is fixed to the outer surface of the partition wall 2 so as to cover the holes 3 and 10. The inside of the head 19 is divided into a suction chamber 21 and a discharge chamber 22 by a partition wall 20. The suction hole 3 is opened to the suction chamber 21 side, and the discharge hole 10 is opened to the discharge chamber 22 side. Further, the head 19 is provided with a suction port 23 communicating with the suction chamber 21 and a discharge port 24 communicating with the discharge chamber 22.

A lead 7 is attached to the lower surface of the partition wall 2 with its free end portion facing the lower end opening of the suction hole 3, and the end surface 8 a of the piston 8 is attached to the partition wall 2. The intake valve is configured to open only when moving away from it. On the other hand, another lead 25 is attached to the upper surface of the partition wall 2 with its free end portion facing the upper end opening of the discharge hole 10, and the end surface 8a of the piston 8 is the partition wall. It constitutes a discharge valve that opens only when approaching 2.

An opening hole 26 is provided in a part of the partition wall 2. The lower end of the open hole 26 is opened at a position separated from the lead 7, or a through hole is formed in a part of the lead 7 aligned with the lower end opening of the open hole 26. . Therefore, the inside of the cylinder portion 1 and the open hole 26 are always in communication with each other.

Further, in the head 19, there is provided an open passage 27 that connects the upper end opening of the open hole 26 and the suction port 23. A cylindrical valve case 28 is provided in the middle of the open passage 27, and the open hole 26 and the suction port 23 are communicated with each other through the inside of the valve case 28. An opening / closing valve 29 is provided in the lower portion of the valve case 28, and an upper portion of the valve case 28 serves as an unload cylinder 30 which constitutes a drive device for opening / closing the opening / closing valve 29.

That is, the through hole 31 formed in the lower side surface of the valve case 28 is communicated with the suction port 23, and the through hole 32 formed in the central portion of the lower end surface is communicated with the open hole 26. Further, a protrusion 33 is formed on the lower surface of the valve case 28 so as to surround the entire circumference of the opening peripheral portion of the through hole 32. A valve element 34 is inserted into the through hole 32 from below. The valve body 34 formed in the inverted mushroom shape has a valve plate 36 fixed to the lower end of a valve rod 35, and the upper surface of the valve plate 36 faces the protrusion 33. That is, the protrusion 33 and the valve plate 36 constitute an on-off valve 29 that opens and closes the lower end opening of the through hole 32.

On the other hand, the valve rod 35 is connected to the central portion of the unload piston 37. The unload piston 37 is fitted in the unload cylinder 30 in an airtight manner and in a freely movable manner. Further, a compression spring 38 is provided between the bottom surface of the valve case 28 and the lower surface of the unload piston 37 to give the unload piston 37 an upward elastic force.

Further, a lid 39 is airtightly attached to the upper end opening of the valve case 28, and the lid 39 is provided with a compressed air inlet 40. The compressed air in the air tank storing the compressed air for braking can be freely fed into the feed port 40 by a pipe (not shown).

In the case of the air compressor of the present invention configured as described above, when the amount of compressed air in the air tank is insufficient, the compressed air is fed into the unload cylinder 30 through the feed port 40. Is not performed, or the pressure of the compressed air fed in is low. As a result, the unload piston 37 and the valve rod 35 are raised by the elastic force of the compression spring 38, the upper surface of the valve plate 36 is pressed against the lower edge of the protrusion 33, and the through hole 32 at the lower end of the valve case 28 is closed. .

When the piston 8 is reciprocated in this state, air is sucked into the cylinder portion 1 from the suction hole 3 as the piston 8 descends, and this air is compressed as the piston 8 rises. From the discharge hole 10 toward the air tank.

When compressed air does not need to be sent out, the compressed air is sent into the unload cylinder 30 by the control mechanism that operates according to the pressure in the air tank, and the unload piston 37 is made elastic by the compression spring 38. It resists and descends. As a result, the upper surface of the valve plate 36 is separated from the lower edge of the protrusion 33, and the through hole 32 at the lower end of the valve case 28 is opened. In this state, the inside of the cylinder portion 1 is open to the atmosphere through the open hole 26, the open passage 27, and the suction port 23.

As a result, even when the piston 8 approaches the partition wall 2, the air is not compressed, and the movement of the piston 8 can be performed with a light force.

[0033]

[Effect of device]

 Since the air compressor of the present invention is constructed and operates as described above, it does not damage the components when switching to the unloading mode, and the pressure in the cylinder does not fluctuate during unloading. Therefore, the operating condition of the engine for driving the air compressor can be stabilized.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a first example of a conventional structure.

FIG. 3 is a sectional view showing the second example.

[Explanation of symbols]

 1 Cylinder part 2 Partition wall 3 Suction hole 4 Unload cylinder 5 Unload piston 5 Rod 7 Lead 8 Piston 8a End face 9 Suction passage 10 Discharge hole 11 Discharge passage 12 Unload cylinder 13 Unload cylinder 14 Unload piston 15 Unload piston 16 valve body 17 valve body 18 space 19 head 20 partition wall 21 suction chamber 22 discharge chamber 23 suction port 24 discharge port 25 lead 26 open hole 27 open passage 28 valve case 29 open / close valve 30 unload cylinder 31 through hole 32 through hole 33 protrusion Article 34 Valve body 35 Valve rod 36 Valve plate 37 Unload piston 38 Compression spring 39 Lid body 40 Inlet port

Claims (1)

[Scope of utility model registration request] 1. A cylinder part having one end closed by a partition wall, a piston that reciprocates in the cylinder part to move the end face of the partition wall toward and away from each other, and a suction member formed on each of the partition walls. Suction valve provided in the hole and discharge hole, and the suction hole portion, and opened only when the end surface of the piston moves away from the partition wall, and opened only when the end surface of the piston, which is provided in the discharge hole portion, approaches the partition wall Discharge valve,
An air compressor having a suction port that communicates with the suction hole and a discharge port that communicates with the discharge hole, and an air compressor that includes a head provided on the upper side of the partition wall. An opening hole having one end opened to the cylinder portion, an opening passage communicating the other end of the opening hole with the suction port, an opening / closing valve provided in the middle of the opening passage, and opening / closing the opening / closing valve. An air compressor characterized by being equipped with a drive device that operates.