JP3979707B2 - Unloader for air compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The unloader for an air compressor according to the present invention constitutes an air brake device for a large vehicle, for example, and is incorporated in an air compressor used to create compressed air for braking. And when discharge of compressed air is unnecessary, the torque required in order to rotationally drive this compressor is reduced.
[0002]
[Prior art]
As a braking device for a large vehicle such as a large truck or a bus, an air brake device that generates a braking force by the force of compressed air is widely used. In such an air brake device, the compressed air created by driving the air compressor by the above-mentioned large vehicle traveling engine is stored in an air tank, and the actuator is operated by the force of the compressed air discharged from the air tank during braking. The friction material is pressed against the inner peripheral surface of the drum and both side surfaces of the disk.
[0003]
The air compressor includes a cylinder portion whose one end is closed by a partition plate, a piston which is driven by the traveling engine and reciprocates in the cylinder portion, and moves its end surface toward and away from the partition plate. A suction port and a discharge port formed in the plate, and a suction valve provided in the suction port portion, which opens only when the end face of the piston moves away from the partition plate; and provided in the discharge port portion; And a discharge valve that opens only when the end surface approaches the partition plate. The air compressor configured as described above compresses the air sucked into the cylinder portion from the suction port as the piston reciprocates, and sends the compressed air from the discharge port toward the air tank. That is, compressed air is discharged from the discharge port and is sent to the air tank through a discharge valve which is a check valve.
[0004]
By the way, the piston always reciprocates when the traveling engine is rotating, whereas when a sufficient amount of compressed air is accumulated in the air tank, the piston is compressed from the discharge port. Not only is it unnecessary to send out air, but the power of the traveling engine is unnecessarily consumed, so that the traveling performance of the vehicle is deteriorated and the fuel consumption is deteriorated. For this reason, 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 unload device that prevents the power of the engine from being wasted is attached to the air compressor as described above.
[0005]
An air compressor incorporating such an unloading device is configured as shown in FIGS. A cylinder head 103 is coupled and fixed to one end portion (the upper end portion in FIG. 5) of the cylinder portion 101 via a partition plate 102, thereby closing one end opening of the cylinder portion 101. In such a cylinder portion 101, a piston 104 is fitted in an airtight manner, and the piston 104 can be reciprocated in the cylinder portion 101 based on rotation of a crankshaft (not shown). A part of the partition plate 102 is provided with a suction port 105 and a discharge port 106, of which the suction port 105 is a suction port 107 provided in the cylinder head 103, and the discharge port 106 is also a discharge port 108. I let you communicate. Further, a suction valve 109 is provided at the suction port 105 portion on the lower surface of the partition plate 102, and a discharge valve 110 is provided at the discharge port 106 portion on the upper surface of the partition plate 102.
[0006]
An open passage 112 for constituting the unload device 111 is provided inside the cylinder head 103, and one end of the open passage 112 is connected to the cylinder portion 101 and the other end is connected to the suction port 107. I am letting. An unload valve 113 is provided in the middle of the open passage 112. The unload valve 113 includes a cylinder cylinder 114, an unloading piston 115 fitted in the cylinder cylinder 114, and a valve body 116. The valve body 116 is given a resilient force toward a valve seat 118 provided at the end of the cylinder cylinder 114 by a compression spring 117.
[0007]
When the compressed air is discharged by an air compressor so as to store a necessary amount of compressed air in the air tank, the piston 104 is reciprocated in the cylinder portion 101 while the unload device 111 is in an inoperative state. That is, the valve body 116 is pressed against the valve seat 118 by the elasticity of the compression spring 117, and the piston 104 is reciprocated while the open passage 112 is closed. As a result, the air sucked into the cylinder portion 101 from the suction port 105 is compressed in the cylinder portion 101 and then discharged from the discharge port 106.
[0008]
On the other hand, when the pressure of the compressed air stored in the air tank becomes sufficiently high and it is not necessary to discharge compressed air from the air compressor any more, the unload device 111 is operated to Prevents power from being wasted. As described above, when the unload device 111 is operated, compressed air is sent to the unload port 119 by an unload signal sent from the pressure regulating valve connected to the air tank. As a result, the unloading piston 115 approaches the valve body 116 and presses the valve body 116 by the push rod 120 to separate the valve body 116 from the valve seat 118. As a result, the inside of the cylinder part 101 and the suction port 107 remain in communication with each other via the open passage 112, and the force required to reciprocate the piston 104 can be reduced.
[0009]
[Problems to be solved by the invention]
The conventional air compressor unloading device constructed and operated as described above has the following problems to be solved. First, the valve body 116 touches high-temperature air that is adiabatically compressed and exists at the top of the cylinder portion 101, and the temperature rises due to the influence of the heat of the air. As a result, with use over a long period of time, the compression spring 117 that presses the valve body 116 may deteriorate, and the elasticity that presses the valve body 116 toward the valve seat 118 may be insufficient.
Second, at the time of unloading, in order to separate the valve body 116 from the valve seat 118, the valve body 116 is pressed by a push rod 120 separate from the valve body 116. When the unloading device is not in operation, there is a slight gap between the end surfaces of the push rod 120 and the valve body 116. For this reason, compressed air is fed into the unload port 119, and after the displacement of the unloading piston 115 is started, the valve body 116 is separated from the valve seat 118 until the unload device 111 is activated. It is inevitable that some time lag will occur.
In view of such circumstances, the unloading device for an air compressor of the present invention realizes a structure that prevents deterioration of the compression spring that presses the valve body of the unloading device and eliminates the operation delay of the unloading device. Invented as much as possible.
[0010]
[Means for solving the problems]
Of the air compressor unloading apparatus according to the present invention, the air compressor unloading apparatus according to the first aspect of the present invention includes a cylinder portion whose one end is closed by a partition plate, and a reciprocating motion in the cylinder portion. A piston that moves and moves its end surface relative to the partition plate, a suction port and a discharge port formed in the partition plate, and a suction port portion of the piston are provided, and the end surface of the piston is the partition plate. A suction valve that opens only when moving away from the suction port, a discharge valve that is provided at the discharge port portion and opens only when the end surface of the piston approaches the partition plate, a suction port that leads to the suction port, and a discharge port that leads to the discharge port And is incorporated into an air compressor including a cylinder head provided on one side of the partition plate on the side opposite to the cylinder portion.
Such an unload device for an air compressor of the present invention is provided inside the cylinder head, and has an open passage with one end communicating with the cylinder portion, a valve seat provided in the middle of the open passage, A valve body provided in a state of being opposed to the valve seat, closing the open passage by contacting the valve seat, and opening the open passage by separating from the valve seat; and one end of the valve body And an actuator having an unloading piston which is provided at the other end of the transmission rod and displaces the transmission rod in the axial direction. The actuator opens the open passage by displacing the transmission rod in the axial direction when discharge of compressed air by an air compressor is unnecessary. The valve seat is provided at the inner peripheral edge of one end of a sleeve arranged in series with the unloading piston, and a plurality of guides each extending in the axial direction of the sleeve are provided on one end surface of the sleeve. Tongue pieces are intermittently provided in the circumferential direction, and the valve body is supported inside the guide tongue pieces so as to be displaceable in the axial direction.
Further, in the air compressor unloading device according to the second aspect of the present invention, the diameter of the unloading device for the air compressor is such that a part of the valve body that is in contact with the valve seat is directed to a surface where one end of the transmission rod is coupled. A conical convex inclined surface inclined in a decreasing direction is used.
[0011]
[Action]
The unloading device for an air compressor of the present invention configured as described above needs to discharge compressed air by the air compressor. When the unloading device is deactivated, the transmission rod is displaced in the axial direction by the actuator. And press the valve body against the valve seat. In this state, the actuator and the cylinder portion are separated from each other, and the actuator does not touch the high-temperature air existing at the top of the cylinder portion. As a result, it is possible to prevent the constituent parts of the actuator from deteriorating due to the heat of the high-temperature air.
Further, when it is not necessary to discharge air by the air compressor and the unloading device is operated, the transmission rod is displaced in the axial direction by the actuator, and the valve body is separated from the valve seat. At this time, the displacement of the actuator is immediately transmitted to the valve body, and the valve body is separated from the valve seat. As a result, there is no time lag before the unload device is activated.
Furthermore, since the valve body is supported by a plurality of guide tongues, the valve body is prevented from wobbling and the close contact between the valve body and the valve seat is improved when the open passage is closed. Efficiency reduction can be prevented.
Further, as the second invention, the adhesion between if surface abutting against the conical convex inclined surfaces on the valve seat part of the valve body, also these valve element and the valve seat during closure of the open channel The air can be prevented from leaking through the release passage, and the efficiency of the air compressor can be prevented from being lowered by providing the unload device .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
1 to 3 show a first example of an embodiment of the present invention. As shown in FIG. 2, the air compressor incorporating the unloading device for the air compressor according to the present embodiment has a cylinder portion 1 whose one end is closed by a partition plate 2, and a reciprocating movement within the cylinder portion 1, and its end face. Is provided with a piston 4 that moves the lens in the distance with respect to the partition plate 2. Of the suction port 5 and the discharge port 6 respectively formed in the partition plate 2, a suction valve 9 that opens only when the end surface of the piston 4 moves away from the partition plate 2 is provided in the suction port 5 portion. A discharge valve 10 that opens only when the end face of the piston 4 approaches the partition plate 2 is provided at the discharge port 6 portion. Also, a cylinder head 3 is provided on one side of the partition plate 2 (upper surface in FIG. 2) on the side opposite to the cylinder portion 1, and a suction port 7 that leads to the suction port 5 and a discharge port 6 are connected to the cylinder head 3. A discharge port 8 is provided.
[0013]
An unloading device 11 of the present invention incorporated in such an air compressor has an open passage 12 provided inside the cylinder head 3. One end (the left end in FIG. 1) of the open passage 12 is connected to the cylinder portion 1 through a first through hole 21 (FIG. 2) provided in the partition plate 2, and the other end is an intermediate portion of a sleeve 22 described below. The suction port 7 communicates with each other through second through holes 23 provided in the section. When the unloading device 11 is operated, the inside of the cylinder portion 1 and the suction port 7 are communicated with each other through the through holes 21 and 23 and the open passage 12.
[0014]
Inside the open passage 12, a sleeve 22 and a cylinder cylinder 14 are provided in series in the axial direction (left and right direction in FIG. 1) in order from one end side communicating with the first through hole 21. Yes. Of these, the sleeve 22 is entirely formed of a metal material in a cylindrical shape. The outer diameter side small diameter portion 24 is provided at the axially intermediate portion of the outer peripheral surface, and the outer diameter side large diameter portion 25a is provided at both axial ends. , 25b are formed. Of these, a locking groove 26 is formed over the entire circumference of the intermediate portion of the outer diameter side large diameter portion 25 a on the one end side, and an O-ring 27 is mounted in the locking groove 26. In a state where the sleeve 22 is inserted into the open passage 12, a portion near the outer periphery of the outer diameter side large diameter portion 25 a contacts a first locking step portion 28 formed on the inner peripheral surface of the open passage 12. The O-ring 27 is in elastic contact with the inner peripheral surface of the open passage 12 over the entire circumference.
[0015]
Further, a flange portion 29 having an outward flange shape is formed on the outer peripheral surface of the outer diameter side large diameter portion 25b on the opposite side (right side in FIG. 1) on the axially central portion (leftward portion in FIG. 1) of the sleeve 22. is doing. The flange portion 29 is inserted into the open passage 12 in a state where the sleeve 22 is inserted into the open passage 12 and the cylinder cylinder 14 is screwed and fixed to the other end portion (the right end portion in FIG. 1) of the open passage 12. Is sandwiched between a second locking step 30 formed on the inner peripheral surface of the cylinder and a base end surface (left end surface in FIG. 1) of the cylinder cylinder 14, and is fixed in the open passage 12.
[0016]
The half of the inner peripheral surface of the sleeve 22 near the one end in the axial direction is an inner diameter side large diameter portion 31, and the other end near the other end is an inner diameter side small diameter portion 32. Then, an inward flange-like locking collar portion 33 is formed at a portion located at one end portion of the inner diameter side small diameter portion 32 at the axial center portion of the sleeve 22. A plurality (four in the illustrated example) of guide tongues 34 and 34 are extended in the axial direction of the sleeve 22 on one end surface (left end surface in FIG. 1) of the sleeve 22. The inner peripheral surfaces of the guide tongue pieces 34 are located on a single cylindrical surface. Further, a portion surrounded by the guide tongues 34 and 34 on the inner peripheral edge of the one end opening of the sleeve 22 is a valve seat 18.
[0017]
On the other hand, the cylinder cylinder 14 is entirely formed of a metal material in a cylindrical shape, and includes a large-diameter cylinder cylinder portion 35 and a small-diameter port portion 36 provided in series in the axial direction. Of these, a male screw 37 is formed on the outer peripheral surface of the cylinder tube portion 35, and the male screw 37 and a female screw 38 formed near the inner peripheral surface opening of the opening passage 12 are screwed together to thereby form the cylinder. The cylinder 14 is fixed to the cylinder head 3. In this state, as described above, the flange portion 29 fixed to the outer peripheral surface of the sleeve 22 is pressed against the second locking step portion 30, and the sleeve 22 is supported by a predetermined portion inside the open passage 12. Fix it. Further, the O-ring 40 is elastically pressed between the flange portion 29 and the bottom surface of the step portion 39 formed on the front end surface of the cylinder cylinder 14 to keep the sleeve 22 and the cylinder cylinder 14 airtight. Plan. Further, an unload port 19 is provided in the center of the port portion 36, and compressed air can be supplied and discharged through the unload port 19 to the inside of the cylinder cylinder portion 35.
[0018]
Unloading piston 15 inside the cylinder tube portion 35 such as described above, as well as displaced freely fitted over the axial direction, the engagement Tometsuba with one side of the unloading piston 15 (the left side in FIG. 1) A compression spring 51 is provided between the portion 33 and an elastic force in a direction away from the sleeve 22 is applied to the unloading piston 15. In this manner, an air cylinder type actuator 41 is configured which displaces the unloading piston 15 in the axial direction by supplying and discharging compressed air to the inside of the cylinder tube portion 35 through the unload port 19. ing.
[0019]
A base end portion (right end portion in FIG. 1) of the transmission rod 42 is coupled and fixed to the central portion of one surface of the unloading piston 15 constituting such an actuator 41. That is, as shown in FIG. 3, a small diameter cylindrical portion 44 formed near the proximal end of the transmission rod 42 is closely fitted in a circular hole 45 formed in the central portion of the unloading piston 15, A male screw portion 46 formed at the base end portion of the transmission rod 42 is screwed into a screw hole 47 formed at the central portion of the unloading piston 15 and further tightened. The transmission rod 42 whose base end portion is coupled and fixed to the unloading piston 15 in this way is inserted through the inner peripheral surface side of the locking flange portion 33 so as to be displaceable in the axial direction, and the distal end portion thereof. Is protruded from one end opening of the sleeve 22. The valve body 16 is fixed to the tip of the transmission rod 42. This valve body 16 is formed in a disk shape as a whole, and the portion facing the valve seat 18 is a conical convex inclined surface 43. Such a valve body 16 has its one-side center part coupled and fixed to the tip of the transmission rod 42 by the same structure as that of the unloading piston 15 described above. In this state, as shown in FIG. 2, the outer peripheral edge of the valve body 16 is close to or slidably contacted with the inner peripheral side surfaces of the guide tongue pieces 34, 34, and can only be displaced in the axial direction of the sleeve 22. Become. The valve body 16 and the transmission rod 42 may be integrally formed.
[0020]
The unloading device for an air compressor of the present invention configured as described above needs to discharge compressed air by the air compressor. When the unloading device 11 is inactivated, the pressure control valve (not shown) The cylinder cylinder 14 constituting the actuator 41 is disconnected from the compressed air source, and the inside of the cylinder cylinder 14 is opened to the atmosphere. In this state, the unloading piston 15 is displaced in the direction away from the sleeve 22 based on the elasticity of the compression spring 51, as shown in FIG. The valve seat 18 is in elastic contact with the entire circumference. As a result, air is compressed in the cylinder portion 1 (FIG. 2), and the compressed air is discharged toward an air tank or the like.
[0021]
In the case of the unloading device for an air compressor of the present invention, the actuator 41 and the cylinder part 1 are in a state where the valve body 16 is in contact with the valve seat 18 in order to discharge compressed air in this way. Separated. The compression spring 51 constituting the actuator 41 does not come into contact with the high-temperature air present at the top of the cylinder part 1. As a result, the components of the actuator 41 such as the compression spring 51 can be prevented from being deteriorated due to the heat of the high-temperature air. In the illustrated example, a cooling jacket 48 (FIG. 2) is provided inside the cylinder head 3 and the partition plate 2 in which the unloading device 11 is incorporated, and cooling water is circulated in the cooling jacket 48 through a water supply port 49. It is free. With such a configuration, the temperature rise of the cylinder head 3 and the partition plate 2 is suppressed, and the charging efficiency of the air compressor is improved. Therefore, if the high temperature air is prevented from directly touching the compression spring 51 when the unload device 11 is not in operation, like the unloading device for an air compressor of the present invention, the temperature of the compression spring 51 is It is possible to prevent a rise so as to impair durability.
[0022]
On the other hand, when it is not necessary to discharge compressed air from the air compressor any more because the pressure of the compressed air stored in the air tank becomes sufficiently high, the unload device 11 is operated. The engine power is prevented from being wasted. When the unloading device 11 is operated in this way, compressed air is fed into the unloading port 19 by an unloading signal sent from a pressure control valve connected to the air tank. As a result, as shown in FIG. 1B, the unloading piston 15 is displaced in a direction approaching the sleeve 22 against the elasticity of the compression spring 51, and the valve body 16 is moved by the transmission rod 42. The valve body 16 is separated from the valve seat 18 by pushing. As a result, the inside of the cylinder part 1 and the suction port 7 remain in communication with each other via the first and second through holes 21 and 23 and the open passage 12, so that the piston 4 can be reciprocated. The required force will be light.
[0023]
In the case of the unloading device for an air compressor of the present invention, when the valve body 16 is separated from the valve seat 18 in this way, the displacement of the unloading piston 15 constituting the actuator 41 is immediately transmitted to the valve body 16. The valve body 16 is separated from the valve seat 18. Therefore, there is no time lag from when the compressed air is fed into the cylinder cylinder 14 and the unloading piston 15 starts to be displaced until the unloading device 11 is activated. As a result, the torque required to drive the air compressor can be immediately reduced, and power loss can be suppressed.
[0024]
Next, FIG. 4 shows a second example of the embodiment of the present invention. In the case of this example, a screw hole is not formed in the unloading piston 15a for constituting an air cylinder type actuator, but instead protrudes from the unloading piston 15a at the end of the transmission rod 42. The transmission rod 42 and the unloading piston 15a are coupled and fixed by screwing the nut 50 into the portion and further tightening. Other configurations and operations are the same as those of the first example described above.
[0025]
【The invention's effect】
Since the unload device for an air compressor of the present invention is configured and operates as described above, the deterioration of the components due to long-term use is prevented, and the durability of the air compressor incorporating the unload device is improved. Can be planned. In addition, it is possible to eliminate the time lag during the operation of the unloading device and to reduce the power loss.
[Brief description of the drawings]
FIGS. 1A and 1B show a first example of an embodiment of the present invention, in which FIG. 1A is a non-operating state of an unloading device, and FIG.
FIG. 2 is a cross-sectional view taken along line XX in FIG.
FIG. 3 is a cross-sectional view showing a coupling portion between a transmission rod and an unloading piston .
4 is a view similar to FIG. 3, showing a second example of an embodiment of the present invention. FIG.
FIG. 5 is a cross-sectional view of an essential part showing an example of an air compressor incorporating a conventional unloading device.
6 is a cross-sectional view taken along line YY of FIG. 5 showing an example of a conventional unloading apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,101 Cylinder part 2,102 Partition plate 3,103 Cylinder head 4,104 Piston 5,105 Suction port 6,106 Discharge port 7,107 Suction port 8,108 Discharge port 9,109 Suction valve 10,110 Discharge valve 11 , 111 Unload device 12, 112 Open passage 113 Unload valve 14, 114 Cylinder cylinder 15, 15a, 115 Unload piston 16, 116 Valve body 117 Compression spring 18, 118 Valve seat 19, 119 Unload port 120 Push rod DESCRIPTION OF SYMBOLS 21 1st through-hole 22 Sleeve 23 2nd through-hole 24 Outer diameter side small diameter part 25a, 25b Outer diameter side large diameter part 26 Locking groove 27 O-ring 28 First locking step part 29 Gutter part 30 Second Locking step portion 31 Inner diameter side large diameter portion 32 Inner diameter side small diameter portion 33 Locking collar portion 34 Guide tongue piece 35 Cylinder Tube portion 36 Port portion 37 Male screw 38 Female screw 39 Step portion 40 O-ring 41 Actuator 42 Transmission rod 43 Inclined surface 44 Small diameter cylindrical portion 45 Circular hole 46 Male screw portion 47 Screw hole 48 Cooling jacket 49 Water supply port 50 Nut 51 Compression spring

Claims (2)

A cylinder portion whose one end is closed by a partition plate, a piston which reciprocates in the cylinder portion and moves its end face to and away from the partition plate, and a suction port and a discharge port respectively formed in the partition plate; A suction valve provided at the suction port portion that opens only when the end surface of the piston moves away from the partition plate; and a discharge valve provided at the discharge port portion and opens only when the end surface of the piston approaches the partition plate. An air compressor incorporated in an air compressor having a valve, a suction port that communicates with the suction port, and a discharge port that communicates with the discharge port, and a cylinder head provided on one side of the partition plate on the side opposite to the cylinder portion An unloading device provided inside the cylinder head and having one end thereof communicated with the cylinder portion, and A valve body provided in a state opposite to the valve seat, closing the open passage by contacting the valve seat, and opening the open passage by separating from the valve seat And a transmission rod having one end coupled to the valve body, and an actuator having an unloading piston provided at the other end of the transmission rod to displace the transmission rod in the axial direction. When it is not necessary to discharge compressed air by a compressor, the transmission rod is displaced in the axial direction to open the opening passage , and the valve seat is located in one end of a sleeve arranged in series with the unloading piston. A plurality of guide tongues, each extending in the axial direction of the sleeve, are intermittently provided in the circumferential direction on one end surface of the sleeve. Is in and, the valve body unloading device for an air compressor which is supported freely displaceable over the axial direction inside the respective guide tongues.   2. The air compressor according to claim 1, wherein a part of the valve body that comes into contact with the valve seat is a conical convex inclined surface that is inclined in a direction in which a diameter decreases toward a surface where one end of the transmission rod is coupled. Unloading device.

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