JP4743834B2 - Protection valve - Google Patents

Description

  The present invention relates to a protection valve used in a vehicle brake system and the like.

In vehicles in which service brakes, parking brakes, clutches, suspensions, or other auxiliary machines are operated with air pressure, protection valves as shown in Patent Documents 1 to 4 are provided in order to increase the reliability of the air system. used.
Hereinafter, the prior art will be described by taking the protection valve disclosed in Patent Document 1 as an example. FIG. 11 shows a circuit diagram of a protection valve (hereinafter abbreviated as “valve”) 110 according to the prior art disclosed in Patent Document 1.

  In FIG. 11, the valve 110 has an inlet 111 connected to a pressure source, an outlet 113 connected to a first main brake circuit 112, an outlet 115 connected to a second main brake circuit 114, and a spring brake circuit 116. And an outlet 119 connected to the auxiliary circuit 118. In addition, a first valve 120 is provided between the inlet 111 and the outlet 113, and similarly, a second valve 121 is provided between the inlet 111 and the outlet 115, and a secondary side (outlet) of the first valve 120. The third valve 122 is provided between the second valve 121 and the outlet 117, and the fourth valve 123 is provided between the secondary side (outlet) of the second valve 121 and the outlet 119. In addition, in the middle of the connection passages 130 and 131 connecting the third valve 122 and the fourth valve 123 to the first valve 120 and the second valve 121, respectively, a check that allows only the flow from the inlet side to the outlet side is allowed. A valve 132 and a check valve 133 are provided.

  The valve 110 is further provided with a first bypass route that bypasses the first valve 120, and the first bypass route allows only a flow from the inlet side to the outlet side, and a check valve 125 and a throttle valve. 126 is provided. Similarly, a second bypass route that bypasses the second valve 121 is provided, and a check valve 128 and a throttle valve 129 that allow only flow from the inlet side to the outlet side are provided in the second bypass route. Yes.

  The valve 110 is characterized in that the inlet 111 and the spring / brake circuit outlet 117 are connected by a passage 134, and the passage 134 allows only the flow from the spring / brake circuit outlet 117 side to the inlet 111 side. A check valve 135 is interposed, and a throttle valve 136 is provided.

  According to this valve 110, for example, when the first main brake circuit 112 fails and the air is released when the vehicle is left in a day and night stop state, the air stored in the air tank of the spring brake circuit 116 is Release to the inlet 111 via the check valve 135 and the throttle valve 136 in the passage 134, and further from the failed first main brake circuit 112 via the first throttle valve 126, the check valve 125 and the outlet 113. Is done. As a result, the pressure of the spring brake circuit 116 decreases, and even if the driver releases the spring brake, air is not supplied to the air chamber of the spring brake device, so the spring brake cannot be released. The vehicle cannot start.

  That is, for example, if the spring brake can be released before the second main brake circuit 114 is effective after the engine is started (after the pressure source is started), the vehicle can be started without the main brake being effective. This is a safety issue. However, according to the valve 110, air escapes from the air chamber of the spring / brake circuit 116, so that the spring / brake cannot be released and the vehicle cannot be started, and the above-described problems can be avoided.

Japanese Patent Laid-Open No. 10-100808 JP 2000-43710 A JP 52-67463 A JP 2000-264193 A

  As described above, when the inlet 111 and the spring / brake circuit outlet 117 are communicated by the passage 134 and the check valve 135 and the throttle valve 136 are provided in the passage 134, the processing of the valve body is complicated. At the same time, the number of parts increases, which tends to increase costs.

  Further, in order to provide the check valve 132 and the check valve 133, the valve main body is divided into two parts as in the protection valve shown in Patent Document 4, and the valve main body is fastened by bolts. It may be necessary to form the film, and in this respect as well, it becomes a barrier to cost reduction and a factor of strength reduction. Therefore, in the case of the protection valve having the passage 134, the check valve 135 and the throttle valve 136, and the check valve 132 and the check valve 133, the cost increase is significant, and the valve body is further divided into two parts. Dividing into two parts has the disadvantage that the strength of the valve body is reduced.

  Accordingly, the present invention has been made in view of such problems, and an object of the present invention is to provide a protection valve having a communication path that communicates an inlet port with an outlet port for a spring / brake circuit. The purpose of this is to improve the strength of the valve body.

  In order to achieve the above object, a protection valve according to a first aspect of the present invention includes an inlet port and a plurality of output ports including a first output port and a second output port, and is connected to the output port. A protection valve that is disposed corresponding to each output port, and a first valve that is connected to the pressure supply means via the inlet port; A first protection valve provided corresponding to the first output port in the flow path from the first chamber to the first output port; and the second protection valve in the flow path from the first chamber to the second output port. A second protection valve provided corresponding to the output port; a first communication path that bypasses the first protection valve and communicates the first chamber and the first output port; the first chamber; Communicates with the second output port A two-way passage, a first check valve provided in the first communication passage and preventing flow from the first output port to the first chamber, and a first check passage provided in the first communication passage. A first throttle valve that throttles the flow rate of the fluid from the first chamber to the first output port, and a second check valve that is provided in the second communication path and blocks the flow from the first chamber to the second output port; The flow rate of the fluid from the second output port to the first output port through the second communication path, the first chamber, and the first communication path in this order is the first communication port. It is adjusted by the first throttle valve provided in the passage.

  According to the above aspect, when a pressure circuit (for example, a service brake circuit) connected to the first output port fails, from a pressure circuit (for example, a spring brake circuit) connected to the second output port, Since fluid (for example, air) flows out from the first output port through the second communication passage, in this example, the inconvenience that the spring brake can be released before the service brake can be used, Can be avoided. Here, the fluid flowing out from the first output port through the second communication path passes through the second output path, the second chamber, the first chamber, and the first communication path in more detail from the second output port. Although it goes to a 1st output port, the flow volume of this fluid is adjusted with the 1st throttle valve provided in the 1st communicating path. That is, the first throttle valve that is used in the normal state (the state in which no pressure circuit has failed) is output to the second output when the abnormality occurs (when the pressure circuit connected to the first output port fails). Since it is configured to be used as a throttle valve that throttles the flow rate of fluid flowing from the port to the first output port, there is no need to provide a dedicated throttle valve in the second communication path when an abnormality occurs, effectively reducing parts costs and processing costs Can be reduced.

A protection valve according to a second aspect of the present invention is the protection valve according to the first aspect, wherein the protection valve includes a third output port and a fourth output port, and extends from the first chamber to the third output port. A third protection valve provided corresponding to the third output port in the flow path, and a fourth protective valve provided corresponding to the fourth output port in the flow path from the first chamber to the fourth output port. A protection valve, a flow path from the first chamber to the second protection valve via the first protection valve, and a flow path from the first chamber to the fourth protection valve via the third protection valve. A second chamber that merges, a third check valve that blocks flow from the second chamber to the first output port, and a fourth check that blocks flow from the second chamber to the third output port. And the first protection valve bypassing the third protection valve A third communication passage that communicates with the third output port, a fifth check valve that is provided in the third communication passage and blocks flow from the third output port to the first chamber, And a second throttle valve that is provided in a three-way passage and throttles a flow rate of fluid from the first chamber toward the third output port.
According to the above aspect, in the four-circuit protection valve further including the third output port and the fourth output port, it is possible to obtain the same effects as the first aspect described above.

  A protection valve according to a third aspect of the present invention is the protection valve according to the second aspect, wherein the valve main body of the protection valve has a first main body portion and a second main body portion extending in a first axial direction and a second axial direction, respectively. And a check valve opening for providing the second check valve, the third check valve, and the fourth check valve. However, it is formed in the position accessible from the outer wall of the said bending part without passing through another member.

  According to the above aspect, it is not necessary to divide the valve body to form a hole for providing a check valve as in the prior art, and a drilling operation is performed directly from the outer wall of the bent portion of the single valve body. It can be performed. Therefore, it is possible to provide a valve body, that is, a protection valve, which does not increase the number of parts and maintains strong strength.

  A protection valve according to a fourth aspect of the present invention is the protection valve according to the second aspect, wherein the third check valve is disposed in the valve body of the protection valve, and the third reverse valve is provided from the first output port. A first opening for forming a flow path toward the check valve and the fourth check valve are disposed, and a flow path from the third output port toward the fourth check valve is formed. A second opening and a third opening for forming a flow path from the second check valve to the first chamber are formed in the first outer wall surface of the valve body, and the third check A fourth opening for forming a flow path from the valve to the second chamber, a fifth opening for forming a flow path from the fourth check valve to the second chamber, and the second A check valve is provided, and a flow path from the second output port to the second check valve is provided. A sixth opening for forming, characterized in that is formed on the second outer wall surface intersecting the first outer wall surface.

  According to the above aspect, the first to sixth openings are formed in the first outer wall surface and the second outer wall surface intersecting with the first outer wall surface, thereby arranging the second to fourth check valves and the check valves. It is possible to form a flow path (hole) that communicates with the valve, so that it is not necessary to divide the valve body to form a hole for providing a check valve as in the prior art. A protection valve can be constructed. Therefore, it is possible to provide a valve body, that is, a protection valve, which does not increase the number of parts and maintains strong strength.

  According to the present invention, the flow rate of the fluid from the second output port to the first output port via the second communication path, the first chamber, and the first communication path in this order is Since it is adjusted by the first throttle valve provided in the communication path, it is not necessary to provide a dedicated throttle valve in the second communication path when an abnormality occurs, effectively reducing the parts cost and processing cost of the protection valve. be able to. Further, it is not necessary to divide the valve body in order to form a hole for providing a check valve as in the prior art, and a single valve body can be obtained. As described above, in the protection valve having the communication path that communicates the inlet port and the outlet port for the spring / brake circuit, the cost can be further reduced and the strength of the valve body can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, FIG. 1 is a circuit diagram of a protection valve according to the present invention, FIG. 2 is an external perspective view of the protection valve, FIG. 3A is a plan view of the protection valve viewed from the G direction in FIG. ) Is a plan view viewed from the H direction, FIG. 4A is a plan view viewed from the J direction, FIG. 4B is a plan view viewed from the K direction, and FIG. 5 is a plan view of FIG. It is the top view seen from F direction. 6 is a sectional view taken along line AA in FIG. 3A, FIG. 7 is a sectional view taken along line BB in FIG. 3B, FIG. 8 is a sectional view taken along line CC in FIG. 5 is a sectional view taken along line DD in FIG. 5, and FIG. 10 is a sectional view taken along line EE in FIG. Note that reference numerals (a) to (n) in the circuit diagram of FIG. 1 correspond to reference numerals (a) to (n) in the cross-sectional views of FIGS.

  The circuit configuration of a protection valve (hereinafter abbreviated as “valve”) 100 according to the present invention will be described first with reference to FIG. The valve 100 generally includes an inlet port and a plurality of output ports. When the pressure circuit connected to any one of the output ports fails and a fluid (air) leaks, the valve 100 accompanies the pressure drop. A protection valve is provided for each output port.

In FIG. 1, reference numeral 10 denotes a pressure supply means including an air compressor, reference numeral 11 denotes a first service brake circuit as a pressure circuit, reference numeral 12 denotes a second service brake circuit as a pressure circuit, and reference numeral 13 denotes a pressure circuit. A spring / brake circuit, reference numeral 14 denotes an auxiliary machine circuit as a pressure circuit.
The pressure supply means 10 is connected to the inlet port 1 of the valve 100, the first service brake circuit 11 is connected to the first output port 21, the second service brake circuit 12 is connected to the third output port 22, and the spring / brake circuit 13 is connected to the first output port 21. The auxiliary output circuit 14 is connected to the second output port 23 and the fourth output port 24, respectively.

  The first chamber (indicated by symbol (a)) is a space connected to the pressure supply means 10 via the inlet port 1, and the flow path from the first chamber (a) to the first output port 21 is the first channel. A first protective valve 2A is provided, and similarly, a third protective valve 2C is provided in the flow path from the first chamber (a) to the third output port 22. In addition, a first communication path 56 that bypasses the first protection valve 2 </ b> A and connects the first chamber (a) and the first output port 21 is provided, and the first communication path 56 is connected to the first output port 21. A first check valve 3A that blocks the flow of air to the first chamber (a) and a first throttle valve 4A that throttles the flow rate of air from the first chamber (a) to the first output port 21 are provided. It has been. Similarly, a third communication path 58 that bypasses the third protection valve 2 </ b> C and communicates the first chamber (a) and the third output port 22 is provided, and the third output port 22 is provided in the third communication path 58. A fifth check valve 3E that blocks the flow of air from the first chamber (a) to the first chamber (a), and a second throttle valve 4B that throttles the flow of air from the first chamber (a) to the third output port 22. Is provided.

  On the other hand, in the flow path from the first chamber (a) to the second output port 23, a second protection valve 2B is provided corresponding to the second output port 23, and similarly, from the first chamber (a) to the fourth output port. In the flow path leading to the output port 24, a fourth protection valve 2 </ b> D is provided corresponding to the fourth output port 24. Further, the flow path from the first chamber (a) to the second protection valve 2B via the first protection valve 2A, and the first chamber (a) to the fourth protection valve 2D via the third protection valve 2C. A second chamber (indicated by reference numeral (b): the flow paths (g) and (h) described later are also included) in which the flow paths merge is provided. Further, the flow path from the second chamber (b) to the first output port 21 is provided with a third check valve 3C for blocking the flow from the second chamber (b) to the first output port 21, A fourth check valve 3 </ b> D for blocking the flow to the third output port 22 is provided in the flow path from the second chamber (b) to the third output port 22.

  In the present embodiment, the flow path from the first chamber (a) to the second protection valve 2B passes through the first protection valve 2A, and the flow from the first chamber (a) to the fourth protection valve 2D. The path passes through the third protection valve 2C. However, you may comprise so that it may reach from the 1st chamber (a) directly to the 2nd protection valve 2B and the 4th protection valve 2D, without going through a protection valve, respectively.

  As a characteristic configuration of the valve 100, a second communication path 57 that connects the first chamber (a) and the second output port 23 is provided, and the second communication path 57 includes the first chamber (a ) To the second output port 23 is provided with a second check valve 3B.

Hereinafter, the operation of the valve 100 configured as described above will be described.
When the pressure supply means 10 is started in a state where the air pressure in each pressure circuit and the valve 10 is zero, compressed air is supplied to the first chamber (a). When the pressure in the first chamber (a) rises to a predetermined pressure, the first protection valve 2A and the third protection valve 2C are opened, and compressed air is supplied to the first service brake circuit 11 and the second service brake circuit 12. .

  Here, the first communication passage 56 and the third communication passage 58 act to open the first protection valve 2A and the third protection valve 2C more quickly. That is, the valve opening pressure of the first protection valve 2A and the third protection valve 2C is large when the pressure difference between the primary side (compressed air input side) and the secondary side (compressed air outlet side) is large (for example, 2). In the case where it is smaller (for example, when compressed air is already supplied to the secondary side), the first communication path 56 and the third communication path 56 are slightly lower than in the case where the compressed air is not supplied to the secondary side. Compressed air is supplied in advance to the secondary side of the first protection valve 2A and the third protection valve 2C by the passage 58, and the first protection valve 2A and the third protection valve 2C are quickly opened by a lower valve opening pressure. ing. The first throttle valve 4A and the second throttle valve 4B act to maintain the first chamber (a) at a predetermined pressure when the first service brake circuit 11 or the second service brake circuit fails (details are given here). Later).

  When the first protection valve 2A and the third protection valve 3C are opened and the respective secondary sides reach predetermined pressures, the third check valve 3C and the fourth check valve 3E are opened, and the compressed air is supplied to the secondary chamber (b). To be supplied. When the pressure in the secondary chamber (b) reaches a predetermined pressure, the second protection valve 2B and the fourth protection valve 2D are opened, and compressed air is supplied to the spring / brake circuit 13 and the auxiliary machine circuit 14. As a result, the first protection valve 2A and the third protection valve 2C are opened before the second protection valve 2B and the fourth protection valve 2D, and the minimum pressure at which the spring / brake circuit 13 and the auxiliary circuit 14 can be used. Since the lowest pressure that can be used by the first service brake circuit 11 and the second service brake circuit is reached before rising, the vehicle can be started in a safe state.

  In the valve 100 configured as described above, for example, when the first service brake circuit 11 fails and the compressed air flows out when the vehicle is stopped (spring / brake operating state), the first protective valve 2A is 2 Closed by pressure drop on the primary and primary sides. Further, the compressed air in the first chamber (a) flows out through the first communication passage 56 and the pressure in the first chamber (a) is reduced, so that the third protective valve 2C is also closed.

  Here, the compressed air of the spring / brake circuit 13 is directed from the second output port 23 to the first output port 21 via the second communication path 57, the first chamber (a), and the first communication path 56 in this order. Thus, the pressure of the spring / brake circuit 13 becomes lower than the lowest usable pressure, that is, the spring / brake cannot be released. This also closes the second protection valve 2B.

Next, when the engine is started and the pressure supply means (air compressor) 10 is operated, the compressed air is again supplied to the first chamber (a), and the first throttle valve 4A acts to cause the first chamber (a) to move. The pressure can be increased to a predetermined pressure. Here, since the pressure on the secondary side of the first protection valve 2A is remarkably reduced and the compressed air remains on the secondary side of the third protection valve 2C, the pressure is higher than the valve opening pressure of the first protection valve 2A. The third protection valve 2C is opened at a low valve opening pressure, and the second service brake circuit 12 is ready for use. Then, the pressure in the secondary chamber (b) rises so that the pressures in the spring / brake circuit 13 and the auxiliary circuit 14 become higher than the lowest usable pressure, and both pressure circuits are ready for use.
As described above, it is possible to prevent the inconvenience that the spring / brake circuit 13 can be released before the second service brake circuit 12 can be used in the failure state of the first service brake circuit 11.

  Here, the flow rate of the compressed air flowing out from the first output port 21 through the second output port 23 through the second communication passage 57, the first chamber (a), and the first communication passage 56 in this order is It is adjusted by the first throttle valve 4A provided in the communication passage 56. That is, since the first throttle valve 4A that is normally used (a state in which no failure has occurred in any of the pressure circuits) is also used when an abnormality occurs, the second communication passage 57 has a dedicated throttle when an abnormality occurs. There is no need to provide a valve, and the parts cost and processing cost of the valve 100 can be effectively reduced.

Subsequently, the structure of the valve 100 described above will be described in detail with reference to FIG.
As shown in FIG. 2, the valve body 30 constituting the base of the valve 100 forms a first body portion 56 and a second body portion 57 that extend in a first axial direction 60 and a second axial direction 61, respectively. It is the single body formed so that it may bend in the bending part 55 and may comprise a substantially L-shaped shape as a whole (refer FIG. 5).

  As shown in FIG. 2 and FIG. 3B, the first outer wall surface 30A, which is one of the two outer wall surfaces forming the bent portion 55, has a first opening 31, a second opening 32, a first As shown in FIG. 2 and FIG. 3 (A), the third opening 33 is formed on the second outer wall surface 30B intersecting with the first outer wall surface (orthogonal in this embodiment). An opening 35 and a sixth opening 36 are formed. These openings will be described in detail later.

The inlet port 1 is formed on the second outer wall surface 30B as shown in the figure, and the first output port 21 and the second port are formed on the surface opposite to the second outer wall surface 30B as shown in FIG. The output port 22, the third output port 23, and the fourth output port 24 are each formed by an opening.
Covers 45A and 45B are attached to the third outer wall surface 30C orthogonal to the first outer wall surface 30A and the second outer wall surface 30B, as shown in FIGS. 2 to 4, and are opposite to the third outer wall surface 30C. Covers 45C and 45D are respectively attached to the fourth outer wall surface 30D which is a surface (hereinafter, these are collectively referred to as “cover 45” as appropriate). The cover 45 covers the opening formed in the valve main body 30 for disposing the first protection valve 2A to the fourth protection valve 2D, and urges the valve bodies constituting the respective protection valves. A coil spring is accommodated (details will be described later), and a cover 45A is provided corresponding to the first protection valve 2A. Similarly, the cover 45B is the second protection valve 2B, and the cover 45C is the third protection valve 2C. In addition, the cover 45D is provided corresponding to each of the fourth protection valves 2D.

  Hereinafter, the internal configuration of the valve 100 will be further described in detail with reference to cross-sectional views. As shown in FIG. 6, the opening that forms the inlet port 1 is formed by making a hole so as to be orthogonal to the second outer wall surface 30B, and the hole includes the third outer wall surface 30C and the third outer wall surface 30C. A first chamber (a) is formed by connecting with a hole 62 extending and penetrating perpendicularly to the fourth outer wall surface 30D. In addition, the hole shown by the code | symbol 33a in FIG. 6 is a hole extended in the paper surface back direction of FIG. 6 (refer also FIG. 7), and is a hole which forms the 3rd opening part 33 shown in FIG. This hole 33a is a hole forming a secondary side (flow path (c)) of the second check valve 3B of FIG. 1 on the circuit diagram, and the second check valve 3B and the first chamber (a) Communicate.

  On the outer wall surface opposite to the second outer wall surface 30B, a first output port 21 and a second output port 22 are formed by drilling holes so as to be orthogonal to the outer wall surface, Then, by connecting to the concave portions 63 and 64 (which form an arc shape as shown in FIG. 8 in a plan view) formed so as to be substantially orthogonal to the third outer wall surface 30C and the fourth outer wall surface 30D, respectively. One flow path (j), (k) is formed.

  Hereinafter, the configuration of the first protection valve 2A will be described with reference to FIG. The first protection valve 2 </ b> A is opened and closed by the contact of the protection valve body 37 with the valve seat 53. The valve body 37 for protection valve is urged in the valve closing direction by a spring (coil spring) 42 through a diaphragm 40 and a spring seat 41, and the spring 42 is held by a cover 45 </ b> A through a spring seat 44. The diaphragm 40 functions to partition the region where the compressed air is interposed from the region where the spring 42 is disposed. Reference numeral 47 denotes a seal cap that closes the opening of the cover 45A.

With the above configuration, when the pressure on the primary side (first chamber (a)) of the first protection valve 2A reaches a predetermined pressure, the valve body 37 for protection valve resists the urging force of the spring 42. It will be separated from and will open. Since the second protection valve 2B, the third protection valve 2C, and the fourth protection valve 2D have the same configuration, the description thereof is omitted below.
However, unlike the second protective valve 2B and the fourth protective valve 2D, the first protective valve 2A and the third protective valve 2C have a protective valve valve body 37 including a check valve and a throttle valve. . In the first protection valve 2A and the third protection valve 2C shown in FIG. 6 and the second protection valve 2B and the fourth protection valve 2D shown in FIG. 10, the same components are indicated by the same reference numerals, and FIG. As shown, the second protection valve 2B and the fourth protection valve 2D are not provided with the valve body 37 for the protection valve, and the diaphragm 40 is brought into contact with and separated from the valve seat 54 by the deformation of the diaphragm 40. Opening and closing is performed.

  On the other hand, the protection valve body 37 is provided with a second throttle valve 4B and a fifth check valve 3E as shown on the third protection valve 2C side in FIG. More specifically, the second throttle valve 4B is formed at a position facing the first chamber (a) in the protective valve valve body 37. The second throttle valve 4B is formed by a minute hole, and a check valve valve body 38 capable of displacing the position for closing and opening the minute hole is urged by the spring 39 in the valve closing direction. It is provided in the valve body 37 for protection valves in the state. A groove for forming a flow path is formed on the surface of the protective valve valve body 37 that is in pressure contact with the diaphragm 40 (not shown), so that when the check valve valve body 38 is separated from the fine hole, 5 The check valve 3E is opened, and the compressed air is guided from the first chamber (a) to the first output port 21. Since the first throttle valve 4A and the first check valve 3A provided on the first protection valve 2A side have the same configuration, the description thereof is omitted.

  Next, the configuration of the second check valve 3B will be described with reference to FIG. As shown in FIG. 7, the second check valve 3 </ b> B is opened and closed when the check valve valve body 48 contacts and separates from the valve seat 46. The check valve body 48 is urged in the valve closing direction by a spring 49, and the spring 49 is held by a stopper 50. Reference numeral 51 denotes an O-ring for sealing, and reference numeral 52 denotes a retainer ring that holds the stopper 50. With the above configuration, when the pressure on the primary side (second output port 23 side: flow path (d)) reaches a predetermined pressure, the second check valve 3B resists the biasing force of the spring 49. The valve body 48 is separated from the valve seat 46 and opened. Since the third check valve 3C and the fourth protection valve 3D shown in FIGS. 8 to 10 have the same configuration, the description thereof will be omitted below.

Subsequently, an opening (hole) formed in the valve body 30 in order to provide the second check valve 3B, the third check valve 3C, and the fourth check valve 3D will be described in detail.
As shown in FIGS. 1 and 2, a third check valve 3C is provided, and a flow path (e) from the first output port 21 (flow path j) to the third check valve 3C is formed. A first opening 31 and a fourth check valve 3D are disposed, and a second opening for forming a flow path (f) from the third output port 22 (flow path k) to the fourth check valve 3D. A portion 32 and a third opening 33 for forming a flow path (c) from the second check valve 3B to the first chamber (a) are formed on the first outer wall surface 30A of the valve body 30. Yes. Also, a fourth opening 34 for forming a flow path (g) from the third check valve 3C to the second chamber (b), and a flow from the fourth check valve 3D to the second chamber (b). A fifth opening 35 for forming the path (h) and the second check valve 3B are disposed, and a flow path (from the second output port 23 (flow path m) to the second check valve 3B ( A sixth opening 36 for forming d) is formed in the second outer wall surface 30B intersecting the first outer wall surface 30A.

  The third check valve 3C will be described in detail by taking the third check valve 3C as an example. As shown in FIG. 1, the third check valve 3C includes the secondary side (first output port 21) of the first protection valve 2A and the second protection valve 2B. Since it is provided between the flow paths connecting the primary side (second chamber (b)), as shown in FIGS. 8 and 9, the first outer wall surface 30A is orthogonal to the first outer wall surface 30A. Thus, the valve arrangement hole 31b (first opening 31) of the third check valve 3C is drilled, and the hole 31a is further drilled so that the secondary side of the first protection valve 2A (flow path (j)) A flow path (e) leading to is formed. Then, as shown in FIG. 8, a hole 34a (opening 34) is drilled from the second outer wall surface 30B so as to be orthogonal to the valve arrangement hole 31b, and a flow path (g) leading to the second chamber (b) is formed. Form. Reference numeral 43 indicates a steel ball for sealing.

As described above, the first opening portion 31 and the fourth opening portion 34 for providing the third check valve 3C are different from the first outer wall surface 30A and the second outer wall surface 30B that form the bent portion 55 of the valve body 30. Since it becomes accessible without using a member, the drilling operation can be performed directly from the first outer wall surface 30A and the second outer wall surface 30B with a drill or the like.
The same applies to the second opening 32 and the fifth opening 35 for providing the fourth check valve 3D, and the third opening and the sixth opening 36 for providing the second check valve 3B. As shown in FIGS. 7 to 10, since the first outer wall surface 30A and the second outer wall surface 30B can be accessed without passing through other members, direct drilling can be performed from the first outer wall surface 30A and the second outer wall surface 30B. It is possible to perform a hole punching operation by, for example.

  By adopting such a configuration, the valve body 30 does not need to be divided into members for forming the check valve opening, and the valve body 30 can be formed as a single body. Thereby, the protection valve which consists of the valve main body 30 which maintained the strong intensity | strength without increasing the number of parts can be provided.

  In the above embodiment, the first axial direction 60 and the second axial direction 61 are orthogonal to each other. However, the check valve disposing opening hole is formed from the first outer wall surface 30A and the second outer wall surface 30B of the bent portion 55. The bending portion 55 may be bent so that the first axial direction 60 and the second axial direction 61 intersect at an obtuse angle or an acute angle within a range in which the opening operation can be realized.

The circuit diagram of the protection valve which concerns on this invention. The perspective view of the protection valve which concerns on this invention. (A) is the top view which looked at the protection valve from the G direction of FIG. 1, (B) is the top view which looked at the same H direction. (A) is the top view which looked at the protection valve from the J direction of FIG. 1, (B) is the top view which looked at the K direction. The top view which looked at the protection valve from the F direction of FIG. 4 (B). AA sectional drawing of FIG. 3 (A). BB sectional drawing of FIG. 3 (B). CC sectional drawing of FIG. 4 (A). DD sectional drawing of FIG. EE sectional drawing of FIG. The circuit diagram of the protection valve which concerns on a prior art.

Explanation of symbols

1 inlet port, 2A first protection valve, 2B second protection valve, 2C third protection valve,
2D 4th protection valve, 3A 1st check valve, 3B 2nd check valve, 3C 3rd check valve,
3D fourth check valve, 3E fifth check valve, 4A first throttle valve, 4B second throttle valve,
10 pressure supply means, 11 first service brake circuit,
12 Second service brake circuit, 13 Hand brake circuit, 14 Auxiliary machine circuit,
21 1st output port, 22 3rd output port, 23 2nd output port,
24 4th output port, 30 Valve body, 30A 1st outer wall surface, 30B 2nd outer wall surface,
31 1st opening part, 32 2nd opening part, 33 3rd opening part, 34 4th opening part,
35 fifth opening, 36 sixth opening, 37 valve body for protection valve, 38 valve body for check valve,
39 Spring, 40 Diaphragm, 41 Spring seat, 42 Spring, 43 Steel ball,
44 Spring seat, 45A-45d Cover, 46 Valve seat, 47 Seal cap,
48 Check valve body, 49 Check valve spring, 50 Stopper, 51 O-ring,
52 retainer ring, 53 valve seat, 54 valve seat, 55 bent portion, 56 first body portion,
57 2nd body part, 60 1st axial direction, 61 2nd axial direction, 62 hole, 63 recessed part,
64 recesses, 100 protection valves

Claims (5)

A plurality of output ports including an inlet port and a first output port and a second output port, and a protection valve that closes as the pressure in the pressure circuit connected to the output port decreases, corresponding to each output port An installed protection valve,
A first chamber connected to the pressure supply means via the inlet port;
A first protection valve provided corresponding to the first output port in a flow path from the first chamber to the first output port;
A second protection valve provided corresponding to the second output port in the flow path from the first chamber to the second output port;
A first communication path that bypasses the first protection valve and communicates the first chamber and the first output port;
A second communication passage communicating the first chamber and the second output port;
A first check valve provided in the first communication path and blocking a flow from the first output port to the first chamber;
A first throttle valve that is provided in the first communication passage and throttles a flow rate of fluid from the first chamber toward the first output port;
A second check valve provided in the second communication path and blocking a flow from the first chamber to the second output port;
A throttle valve that functions in a fluid flow path from the second output port to the first output port via the second communication path, the first chamber, and the first communication path in this order is the second communication port. The flow rate of the fluid from the second output port to the first output port is adjusted by the first throttle valve provided in the first communication passage without being arranged in the passage ,
The first protection valve has a configuration in which the valve is opened and closed by contacting and separating the valve body for the protection valve with respect to the valve seat,
The valve seat and the valve body for the protective valve are provided in an opening formed in a valve body of the protection valve;
A spring that urges the valve body for the protective valve toward the valve seat is housed in a cover that is provided separately from the valve body and covers the opening,
The protective valve body is biased by the spring via a diaphragm provided between the cover and the valve body,
The diaphragm provides a partition between a region in which the fluid in the opening, where the valve seat and the valve body for the protective valve are provided, and a region in which the fluid outside the opening, which is provided with the spring, is not provided. Being
Protection valve characterized by that. 2. The protection valve according to claim 1 , wherein the first throttle valve is configured by a fine hole formed on a side facing the first chamber in the protective valve body,
A valve body for a check valve provided inside the valve body for the protective valve so that the first check valve is displaceable between a position for closing and opening the fine hole;
And a check valve spring provided inside the protective valve valve body for biasing the check valve valve body in a valve closing direction, and the check valve valve body opens the fine hole. In this case, the protective valve body has a configuration in which a flow path is formed via a flow path forming groove formed on a surface in pressure contact with the diaphragm so that the first check valve is opened. ing,
Protection valve characterized by that. In Claim 1 or 2 , the protection valve comprises a third output port and a fourth output port,
A third protection valve provided corresponding to the third output port in the flow path from the first chamber to the third output port;
A fourth protection valve provided corresponding to the fourth output port in the flow path from the first chamber to the fourth output port;
A second channel where the flow path from the first chamber to the second protection valve via the first protection valve and the flow path from the first chamber to the fourth protection valve via the third protection valve merge. Room,
A third check valve for blocking flow from the second chamber to the first output port;
A fourth check valve for blocking flow from the second chamber to the third output port;
A third communication path that bypasses the third protection valve and communicates the first chamber and the third output port;
A fifth check valve provided in the third communication path and blocking a flow from the third output port to the first chamber;
A second throttle valve which is provided in the third communication path and throttles the flow rate of the fluid from the first chamber toward the third output port;
A protection valve characterized by comprising 4. The valve body of the protection valve according to claim 3 , wherein the valve body of the protection valve is bent as a whole at a bent portion so as to form a first body portion and a second body portion extending in a first axial direction and a second axial direction, respectively. An opening for the check valve for forming the second check valve, the third check valve, and the fourth check valve is integrally formed without any other member from the outer wall of the bent portion. Formed in an accessible location,
Protection valve characterized by that. The valve body of the protection valve according to claim 3 ,
A first opening for disposing the third check valve and forming a flow path from the first output port to the third check valve;
A second opening for disposing the fourth check valve and forming a flow path from the third output port to the fourth check valve;
A third opening for forming a flow path from the second check valve to the first chamber is formed on the first outer wall surface of the valve body;
A fourth opening for forming a flow path from the third check valve to the second chamber;
A fifth opening for forming a flow path from the fourth check valve to the second chamber;
The second check valve is provided, and a sixth opening for forming a flow path from the second output port to the second check valve intersects the first outer wall surface. Formed on the outer wall,
Protection valve characterized by that.

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