JP5691857B2 - Gas pump - Google Patents

Description

  The present invention includes a piston in a cylinder that can freely reciprocate, a pressure operation chamber on a cylinder head side, a drive chamber that transmits a reciprocating drive force to the piston on a side opposite to the pressure operation chamber, and a reciprocating operation of the piston. And a valve unit that controls supply and discharge of gas to and from the pressure operation chamber, and further, a ventilation port is provided in the drive chamber for sending the gas inside the drive chamber out of the cylinder in response to the operation of the piston in the intake direction. The present invention relates to a gas pump provided.

  There exists patent document 1 shown below as prior art document information relevant to this kind of gas pump. In the vacuum pump (gas pump) described in Patent Document 1, the vacuum exhaust discharged from the exhaust port of the cylinder (pressure operation chamber) is once taken into the housing (drive chamber) by a conduit to reduce pressure fluctuation due to exhaust pulsation. Then, the air is discharged to the outside through the exhaust port (ventilation port) of the housing. Furthermore, in the vacuum pump described in Patent Document 1, a throttle valve is provided at the exhaust port of the housing, and a control device that controls the opening degree of the throttle valve according to the amount of suction into the vacuum pump measured by a flow meter is provided. Yes.

  Therefore, since there is no pressure loss in the housing when the vacuum pump is evacuated, less power is required for the reciprocating operation of the piston, and since the exhaust pressure of the vacuum pump pushes up the piston, the vacuum pump is driven. It is said that the motive power required for this is the same level as when the housing is sealed, and at the same time the exhaust noise can be reduced.

JP 2007-291940 A (paragraph 0012, paragraph 0014, FIG. 3)

  However, in Patent Document 1, when the exhaust port (ventilation port) or the throttle valve of the housing (drive chamber) is blocked for some reason such as icing, the internal pressure of the housing (drive chamber) is free from the piston. Therefore, there has been a problem that the capacity of the vacuum pump (gas pump) is lowered due to a rise to a level that hinders reciprocal movement.

  Therefore, in view of the problems given by the gas pump according to the prior art exemplified above, the object of the present invention is unlikely to affect the performance of the gas pump even when the vent of the drive chamber is blocked for some reason. It is to provide a gas pump.

The characteristic configuration of the gas pump according to the present invention is as follows:
A piston is provided inside the cylinder so as to be able to reciprocate freely, a pressure operation chamber is provided on the cylinder head side, and a drive chamber is provided on the opposite side of the pressure operation chamber to transmit the reciprocating drive force to the piston. A valve unit for controlling supply and discharge of gas to and from the pressure operation chamber,
A silencer chamber is provided as an exhaust part for exhausting the exhaust discharged from the valve unit to the outside of the device,
A pressure release machine is provided for adjusting the deviated pressure when the pressure in the driving chamber or the silencer chamber deviates from a predetermined range ;
The pressure operation chamber constitutes a negative pressure chamber;
The pressure release mechanism includes a first pipe part communicating with the valve unit, a second pipe part communicating with the silencer chamber, and the first pipe part and the second pipe part outside the negative pressure chamber. One end is constituted by a hose that is connected and is disconnected from the first pipe part or the second pipe part by an excessive internal pressure of the silencer chamber .

In the gas pump according to the above characteristic configuration, when the pressure of the driving chamber or the silencer chamber deviates from the predetermined range, the pressure of at least one of the driving chamber and the silencer chamber is adjusted to the predetermined range by the pressure release mechanism. It is possible to prevent the drive chamber and the silencer chamber from being damaged by abnormal pressure (high pressure or low pressure). In addition, abnormal noise such as air sound that is not normally heard occurs based on the pressure adjustment operation by the pressure release mechanism, so that the user can know the pressure abnormality of the driving chamber and silencer chamber at an early stage, The effect of prompting a countermeasure for eliminating the pressure abnormality is obtained.
In this configuration, when the hole that communicates the silencer chamber with the outside air is blocked for some reason, the pressure in the silencer chamber increases abnormally, so that one end of the hose is connected from the first pipe section or the second pipe section by this abnormal pressure. By releasing the pressure, the pressure in the silencer chamber is released.
If it is this structure, since a pressure release mechanism is comprised with a hose, attachment is easy. In addition, as a method of adjusting the pressure when the internal pressure becomes excessive, a phenomenon that is apparent in appearance that either one of both ends of the hose comes out of the pipe portion occurs. It is easy to understand and advantageous. In addition, after solving the cause of the excessive internal pressure, the operation of reconnecting the end of the disconnected hose to the original pipe is also facilitated.

  According to another characteristic configuration of the present invention, a connection force between one end of the hose and the first pipe portion and a connection force between the other end of the hose and the second pipe portion are different from each other. It is in the point which is comprised.

  With this configuration, when the internal pressure is increased compared to a configuration in which the value of the internal pressure required to disconnect from the corresponding pipe part between the one end and the other end of the hose is equivalent. Since it is possible to grasp in advance which one of the one end and the other end is to be disconnected, it is advantageous because it is possible to predict in advance the nature of the noise generated by the disconnection. In addition, it is possible to know in advance whether one end or the other end will be disconnected when the internal pressure increases, so after solving the cause of the excess internal pressure, the end of the disconnected hose The operation of reconnecting to the pipe part is further facilitated.

  Another characteristic configuration of the present invention is that the first tube portion and the second tube portion are arranged facing each other.

  If it is this configuration, the exhaust of gas from the negative pressure chamber to the silencer chamber is performed smoothly during normal operation, compared to the configuration in which the first tube portion and the second tube portion are angled with each other, In addition, since the first tube portion and the second tube portion do not easily protrude from the outer shape of the cylinder in plan view, the outer shape of the gas pump can be made more compact as a result.

  Another characteristic configuration of the present invention is that the hose is bent and disposed.

  In this configuration, compared to the configuration in which the hose is arranged linearly, the force acting on the inside of the hose from the excessive internal pressure of the silencer chamber causes the one end of the hose to be connected to the first pipe portion or the second pipe portion. Therefore, the hose is reliably disconnected from the first pipe part or the second pipe part by the excessive internal pressure of the silencer chamber.

  In another feature of the present invention, the pressure release mechanism is temporarily disengaged by the pressure release hole that communicates at least one of the drive chamber and the silencer chamber with the outside, and the deviated pressure. And a closing means for closing the pressure release hole.

  With this configuration, when the driving chamber or the silencer chamber reaches an abnormal pressure (high pressure or low pressure) that deviates from a predetermined range, the closing means is disengaged from the pressure release hole, and the driving chamber is released by disengaging the closing means. Or the pressure in the silencer chamber returns to the specified range. However, since the closing means closes the pressure release hole again, as a result, abnormal noise due to repeated closing and release of the pressure release hole by the closing means may cause the user to abnormally pressure the drive chamber and silencer chamber. Can be known at an early stage, and it is possible to obtain an effect of prompting a countermeasure for eliminating the pressure abnormality.

  Another feature of the present invention is that a vent hole is provided in the drive chamber for sending the gas inside the drive chamber to the silencer chamber in response to the operation of the piston in the intake direction.

  With this configuration, since the pressure increase in the drive chamber based on the operation of the piston in the intake direction is suppressed, less power is required for the reciprocating operation of the piston. Also, with this configuration, the flow of air from the negative pressure chamber to the drive chamber is allowed when the piston is operated in the exhaust direction, and the flow of air from the negative pressure chamber to the drive chamber is performed when the piston is operated in the suction direction. In the case of a configuration including a piston ring or the like in which the piston is prevented, an undesirable phenomenon in which the driving chamber gradually becomes high pressure due to repeated operation of the piston in the suction direction is also suppressed.

Another feature of the present invention is as follows:
The pressure operation chamber constitutes a negative pressure chamber;
The pressure release mechanism connects the first tube portion communicating with the drive chamber, the second tube portion communicating with the silencer chamber, and the first tube portion and the second tube portion outside the drive chamber. In addition, one end is constituted by a hose that is disconnected from the first pipe part or the second pipe part due to excessive internal pressure of the drive chamber or the silencer chamber.

  In this configuration, when at least one of the hole for communicating the silencer chamber and the outside air and the vent for sending the gas inside the drive chamber to the silencer chamber is blocked for some reason, the drive chamber or the silencer chamber Since the pressure is abnormally increased, the pressure in the drive chamber or the silencer chamber is released by disconnecting one end of the hose from the first tube portion or the second tube portion due to the abnormal pressure.

  If it is this structure, since a pressure release mechanism is comprised with a hose, attachment is easy. In addition, as a method of adjusting the pressure when the internal pressure becomes excessive, an externally apparent operation is performed in which either end of the hose comes out of the pipe part. It is easy to understand and advantageous. In addition, after solving the cause of the excessive internal pressure, the operation of reconnecting the end of the disconnected hose to the original pipe is also facilitated.

  According to another characteristic configuration of the present invention, a connection force between one end of the hose and the first pipe portion and a connection force between the other end of the hose and the second pipe portion are different from each other. It is in the point which is comprised.

  In this configuration, when the internal pressure is increased, the one end and the other end are compared with the configuration in which the value of the internal pressure required to be disconnected from the corresponding pipe portion is equal between the one end and the other end. Since it is possible to grasp in advance which one of the other ends is disconnected, it is advantageous because it is possible to predict in advance the nature of the noise generated by the disconnection. In addition, it is possible to know in advance whether one end or the other end will be disconnected when the internal pressure increases, so after solving the cause of the excess internal pressure, the end of the disconnected hose The operation of reconnecting to the pipe part is further facilitated.

It is a partially broken side view which shows the gas pump which concerns on this invention. It is sectional drawing which shows the effect | action of a piston ring. It is sectional drawing which shows the effect | action of a relay exhaust hose. It is sectional drawing which shows the effect | action of a relief valve. It is a top view which shows the gas pump by 3rd Embodiment.

EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated, referring drawings.
[First Embodiment]
FIG. 1 shows a reciprocating type vacuum pump as an example of a gas pump according to the present invention. The vacuum pump includes a cylindrical cylinder 1 and a piston 2 disposed inside the cylinder 1 so as to be capable of reciprocating along an axis X. A negative pressure chamber A (an example of a pressure operation chamber) is disposed on the cylinder head side in the cylinder 1, and a drive chamber B disposed on the opposite side of the negative pressure chamber A along the axis X reciprocates with the piston 2. A crank mechanism C that provides driving force is accommodated.

The end of the cylinder 1 on the cylinder head side is provided with a valve unit V that controls supply and discharge of air (an example of gas) to the negative pressure chamber A in accordance with the reciprocating operation of the piston 2.
A drive chamber B that houses a crank mechanism C is disposed in a pump housing 3 that is airtightly connected to the other end of the cylinder 1.

  An electric motor 4 for driving the crank mechanism C is disposed outside the pump housing 3. The crank mechanism C includes a crank arm 5 that rotates integrally with the output shaft 4 </ b> A of the electric motor 4, and a connecting rod 6 that connects the output shaft of the crank arm 5 and the piston 2.

  The valve unit V includes a casing 21 connected to the cylinder head side of the cylinder 1 and a cover plate 24 that blocks the intake space 21A and the exhaust space 21B formed in the casing 21 from the outside. An intake valve 22 is disposed between the intake space 21A and the negative pressure chamber A of the casing 21, and an exhaust valve 23 is disposed in the exhaust space 21B. The casing 21 and the cover plate 24 are hermetically connected to the cylinder head side of the cylinder 1 by a plurality of connecting bolts 10 in which male screw portions are screwed to the pump housing 3.

The tube 25 connected to the intake space 21A via the cover plate 24 communicates with an external object (such as a brake booster).
The intake valve 22 is made of a material that can be flexibly deformed, such as rubber or resin. The intake valve 22 is in close contact with the valve casing 21 when blocking the air flow, and the valve casing 21 when allowing the air flow. It is elastically deformed so as to form a space that allows air flow between them.

  The exhaust valve 23 is configured to be urged in the closing direction by a spring 23S. When the flow of air is blocked, the outer periphery closely contacts the valve body 21 by the urging force of the spring 23S, and the air flow is reduced. In the case of permitting, the outer peripheral portion rises from the valve body 21 against the urging force of the spring 23S to form a space that allows the flow of air.

  A cylindrical first pipe portion 26 that communicates with the exhaust space 21 </ b> B protrudes toward the pump housing 3 from a position opposite to the intake space 21 </ b> A across the exhaust space 21 </ b> B of the valve casing 21.

  A driving chamber B is formed by closing an opening formed on the opposite side of the pump housing 3 from the electric motor 4 by a plate-like closing member 7. The drive chamber B communicates with the internal space of the path block 15 only through the relatively small vent 7 </ b> A drilled on the opposite side of the piston 2 from the center along the axis X of the closing member 7. The path block 15 and the closing member 7 are simultaneously connected and fixed to the pump housing 3 by a plurality of fixing bolts 8.

Near the center of the lower surface of the path block 15, a relatively small opening 15 </ b> A that connects the internal space of the path block 15 with the space outside the pump is formed.
Further, the second block 16 communicating with the internal space of the path block 15 is provided in the path block 15 so as to project toward the valve unit V. The second pipe portion 16 of the path block 15 and the first pipe portion 26 of the valve casing 21 are connected by a relay exhaust hose 9 made of an elastic material.

  When this vacuum pump is used as a negative pressure source for a brake booster (not shown) for a vehicle, the intake valve from the negative pressure target (such as a brake booster) is activated by the piston 2 acting in the intake direction (right side in FIG. 1). A negative pressure is created by sucking air into the negative pressure chamber A via 22. Further, air is exhausted from the negative pressure chamber A to the outside of the cylinder 1 through the exhaust valve 23 by the operation of the piston 2 in the exhaust direction (left side in FIG. 1). In addition, this vacuum pump is not restricted to what is used for a motor vehicle, It can be used also for the other apparatus which requires a negative pressure, The thing which targets gas other than air as a fluid may be used.

Note that the air pressure in the drive chamber B rises momentarily according to the operation of the piston 2 in the intake direction, but the discharge of the air in the drive chamber B to the outside of the vacuum pump is routed through the vent hole 7A of the closing member 7 and the path. By allowing the opening 15A of the block 15 to allow, the abnormal increase in the air pressure in the driving chamber B is suppressed.
That is, when the piston 2 is operated in the exhaust direction, the air in the negative pressure chamber A is exhausted from the opening 15A to the outside of the vacuum pump via the path block 15, but also when the piston 2 is operated in the intake direction, The air in the driving chamber B is discharged from the open port 15A to the outside of the vacuum pump through the path block 15.

With respect to the operation of the piston 2 in the exhaust direction, a first exhaust path E is formed from the negative pressure chamber A to the opening 15A through the exhaust space 21B of the valve casing 21, the relay exhaust hose 9, and the internal space of the path block 15. Is done.
Further, with respect to the operation of the piston 2 in the intake direction, a second exhaust path F is formed from the drive chamber B through the vent hole 7A and the internal space of the path block 15 toward the open port 15A.
The air in the negative pressure chamber A and the air in the drive chamber B are basically all configured to go to the opening 15A through the air filter 17 disposed in the merge space G of the first exhaust path E and the second exhaust path F. Has been.

The interior space of the path block 15 constitutes an exhaust part that exhausts the exhaust discharged from the valve unit V and the vent 7A to the outside of the apparatus, and at the same time, a silencer chamber for silencing the exhaust noise accompanying the reciprocating movement of the piston 2 S is constituted.
The silencer chamber S is constituted by a donut-shaped space surrounding the air filter 17 in an annular shape. For the air filter 17, wool felt having a dust removal performance, paper material, urethane foam or the like is used.

(piston ring)
As shown in FIG. 2, an annular groove 2G is formed on the entire outer surface of the piston 2, and a piston ring 30 is engaged inside the annular groove 2G. Since the thickness along the axis X of the piston ring 30 is less than the groove width of the annular groove 2G, the piston ring 30 can be displaced along the axis X (the operation direction of the piston 2) inside the annular groove 2G. It has become.
A piston guide bush 31 is fitted on the outer periphery of the piston 2, the piston ring 30 and the piston guide bush 31 are in contact with the inner peripheral surface of the cylinder 1, and the outer periphery at both ends of the piston 2 is in contact with the inner peripheral surface of the cylinder 1. It is configured not to.

  The annular groove 2G includes a first side wall 2Ga on the negative pressure chamber A side, a second side wall 2Gb on the drive chamber B side, and an inner peripheral bottom wall 2Gc extending generally parallel to the axis X so as to be sandwiched therebetween. have. The piston ring 30 has a triple structure in which three rings of an inner ring 30A, an intermediate ring 30B, and an outer ring 30C are overlapped in the radial direction.

  The inner ring 30A is made of stainless steel, and the intermediate ring 30B and the outer ring 30C are made of tetrafluoroethylene resin. A slit (not shown) is formed at one place in the circumferential direction of the inner ring 30A, the intermediate ring 30B, and the outer ring 30C for temporarily expanding the inner diameter when the piston ring 30 is fitted into the annular groove 2G. ing. By disposing the slit of the intermediate ring 30B about 180 degrees different from the slit of the inner ring 30A, and disposing the slit of the outer ring 30C about 180 degrees different from the position of the slit of the intermediate ring 30B. The airtightness of the piston 2 is improved.

  Since the piston ring 30 is fitted into the inner peripheral surface of the cylinder 1 in a state that resists the urging force of the inner ring 30 </ b> A in the diameter increasing direction, the outer periphery of the outer ring 30 </ b> C is An annular gap is formed between the inner peripheral surface of the inner ring 30A and the bottom wall 2Gc of the annular groove 2G.

  A plurality of communication holes 2T for communicating the bottom wall 2Gc of the annular groove 2G and the internal space 2TM of the piston 2 are formed inside the piston 2, and the communication holes 2T communicate with the driving chamber B via the internal space 2TM. doing. When the piston 2 operates in the suction direction, the piston ring 30 is displaced in the direction of the first side wall 2Ga due to frictional force and inertia with the inner peripheral surface of the cylinder 1 and is brought into close contact with the first side wall 2Ga, thereby causing negative pressure. Air flow from the chamber A to the communication hole 2T is blocked. Conversely, when the piston 2 operates in the exhaust direction, the piston ring 30 is displaced in the direction of the second side wall 2Gb and comes into contact with the second side wall 2Gb, so that there is a gap between the piston ring 30 and the first side wall 2Ga. Is formed to allow air flow from the negative pressure chamber A to the drive chamber B through the communication hole 2T.

  That is, when the piston 2 operates in the intake direction, the piston ring 30 is in close contact with the first side wall 2Ga, so that the air flow from the negative pressure chamber A to the drive chamber B is prevented. By the operation of the piston 2, the intake valve 22 is opened and the air from the tube 25 is sucked into the negative pressure chamber A to apply a negative pressure. At the same time, the air in the drive chamber B is supplied from the vent 7A to the second. It is sent to the exhaust path F and discharged from the opening 15A to the outside of the pump. As described above, when air is sent to the second exhaust path F, the exhaust noise is reduced by the silencer chamber S in the path block 15.

  On the other hand, when the piston 2 operates in the exhaust direction, the exhaust valve 23 is opened, the air in the negative pressure chamber A is sent to the first exhaust path E, and at the same time, the drive chamber B tends to be in a negative pressure state. . However, the negative pressure tendency of the drive chamber B based on the movement of the piston 2 in the exhaust direction is caused by the piston ring 30 and the first side wall 2Ga in which a part of the air in the negative pressure chamber A moves relatively to the drive chamber B side. Since it is reduced by entering the driving chamber B through the communication hole 2T from the gap between them, a phenomenon in which external air is sucked into the driving chamber B from the vent 7A is suppressed.

  In addition, since the second exhaust path F that sends air to the vent hole 7A joins the first exhaust path E in the merge space G, it is also sucked even when air is sucked into the drive chamber B by negative pressure. At least a part of the air is derived from the first exhaust path E, and the amount of outside air sucked from the opening 15A is reduced. Moreover, since a small amount of outside air sucked from the opening 15A is also filtered by the air filter 17, there is little possibility that dust and moisture (moisture) enter the driving chamber B together with the outside air.

  Further, when the piston 2 operates in the exhaust direction, the air in the negative pressure chamber A flows directly to the drive chamber B through the communication hole 2T, so that the drive load fluctuates due to the negative pressure in the drive chamber B. [Suppressed to stabilize the driving torque of the electric motor 4. Furthermore, since the electric motor 4 is driven with a constant load in this way, fluctuations in the electric power supplied to the electric motor are reduced and the durability of the electric motor 4 is improved. Further, according to the reciprocating operation of the piston 2, the air in the first exhaust path E and the second exhaust path F flows intermittently to generate a flow noise, but the silencer chamber S suppresses this flow noise.

(Pressure release mechanism)
When the pressure in the driving chamber B or the silencer chamber S deviates from a predetermined range due to some cause, for example, clogging due to icing or dust of water located in the vent 7A, the opening 15A or the air filter 17, A pressure release mechanism that adjusts the pressure of at least one of the drive chamber B and the silencer chamber S by the deviating pressure is provided.

  The pressure release mechanism provided in the vacuum pump shown in FIG. 1 is configured such that when the pressure in the silencer chamber S deviates from a predetermined range, the pressure release mechanism that adjusts the pressure in the silencer chamber S by the deviated pressure is the valve casing 21. The relay exhaust hose 9 connects the first pipe part 26 and the second pipe part 16 of the path block 15 in an airtight manner.

  In particular, the internal pressure of the silencer chamber S required for forcibly disconnecting one end of the relay exhaust hose 9 from the first pipe portion 26 of the valve casing 21 is the same as that of the path block 15. The relay exhaust hose 9 is provided only at the tip of the second pipe part 16 of the path block 15 so as to be surely smaller than the internal pressure value of the silencer chamber S required for forcibly disconnecting from the two pipe parts 16. An annular enlarged portion 16A is provided as a retaining means.

In response to an abnormal increase in the internal pressure of the silencer chamber S due to an abnormality in the opening 15A or the air filter 17, the relay exhaust hose 9 as a pressure release mechanism falls out of the first pipe portion 26 of the valve casing 21, and thereafter the piston Since the exhaust from the negative pressure chamber A due to the movement of the exhaust gas 2 to the exhaust side is directly exhausted from the first pipe portion 26 of the valve casing 21 without going through the silencer chamber S, the exhaust sound is silenced. Without leaking directly to the outside, abnormality of the opening 15A or the air filter 17 is indicated.
In this embodiment, the action of the pressure release mechanism is not observed for an abnormal increase in the internal pressure of the drive chamber B based on the abnormality of the vent 7A.

  In the example shown in FIG. 1, the first pipe portion 26 of the valve casing 21 and the second pipe portion 16 of the path block 15 are arranged to face each other so as to share an axial center, and the first and second pipe portions 26, 16 are connected by a straight relay exhaust hose 9.

  However, by using the relay exhaust hose 9 having an extra length, the relay exhaust hose 9 curved in the vicinity of the intermediate portion or the like connects the first and second pipe portions 26 and 16 arranged opposite to each other. You may implement with the form. In the configuration of the curved relay exhaust hose 9, one end of the relay exhaust hose 9 is more reliably disconnected from the first pipe portion 26 or the second pipe portion 16 due to the excessive internal pressure of the silencer chamber S.

Even in the case of a vacuum pump in which the piston ring 30 having the action of moving part of the air in the negative pressure chamber A to the drive chamber B when the piston 2 moves to the exhaust side is omitted, the relay exhaust hose 9 ( The effect of the pressure release mechanism is obtained.
That is, in the vacuum pump in which the piston ring 30 is omitted, the tendency of the pressure in the negative pressure chamber A to increase due to the movement of the piston 2 to the exhaust side is higher than that of the vacuum pump provided with the piston ring 30. This is because a remarkable tendency is observed based on the abnormality of the filter 17.

(Modification)
In the modification illustrated in FIG. 3, the second pipe portion 16 and the valve casing of the path block 15 are surely pulled out from the first pipe portion 26 based on a predetermined internal pressure of the silencer chamber S so that the relay exhaust hose 9 is surely dropped from the first pipe portion 26. The first pipe portions 26 are arranged so as to be displaced to the left and right in a plan view so as not to face each other.

  That is, as shown by a two-dot chain line in FIG. 3, the relay exhaust hose 9 as a pressure release mechanism is connected to the valve casing against an abnormal increase in the internal pressure of the silencer chamber S due to the abnormality of the opening 15A or the air filter 17. 21 and the exhaust from the negative pressure chamber A due to the movement of the piston 2 to the exhaust side from the first pipe portion 26 of the valve casing 21 to the outside without passing through the silencer chamber S. Since the exhaust gas is directly exhausted, an abnormality of the opening 15A or the air filter 17 is indicated by directly leaking to the outside without the exhaust sound being silenced.

  Alternatively, the first and second pipe portions 26 and 16 may be disconnected from the first pipe portion 26 or the second pipe portion 16 more reliably by the excessive internal pressure of the silencer chamber S. Are arranged so as to face each other in the same direction, for example, to be generally parallel to each other in the downward direction or the lateral direction, and the first and second pipe portions 26 and 16 are necessarily curved near the intermediate portion or the like. The relay exhaust hose 9 may be connected.

[Second Embodiment]
In FIG. 1, the pressure release hole 3H is formed in the wall surface facing the piston 2 of the pump housing 3, and the relief valve RV installed so as to close the pressure release hole 3H has a constant pressure in the drive chamber B. The pressure release mechanism that is temporarily released when the pressure exceeds is established.

  As shown in FIG. 4, the relief valve RV includes a cylindrical main body 32 screwed into the female screw portion of the pressure release hole 3 </ b> H, and a disc-shaped cover fixed near the outlet of the internal space 32 </ b> V of the cylindrical main body 32. A member 33, a valve body 34 (an example of a closing means) disposed closer to the driving chamber B than the cover member 33 of the internal space 32V, and a coil spring 35 interposed between the cover member 33 and the valve body 34 And have.

A through hole 33H is provided at the center of the cover member 33, and the coil spring 35 applies a biasing force that presses the valve body 34 against an annular closing surface 32F formed in the internal space 32V.
In a situation where there is no abnormality in the vent 7A, the opening 15A and the air filter 17, the silencer is activated by the operation of the piston 2 in the exhaust direction or even if the drive chamber B temporarily becomes high pressure by the operation of the piston 2 in the intake direction. Even when the chamber S temporarily becomes high pressure, the relief valve RV is maintained closed by the valve body 34.

  On the other hand, when the pressure in the drive chamber B exceeds a predetermined value defined by the biasing force of the coil spring 35 due to an abnormality in the vent 7A, the opening 15A or the air filter 17 (an example of deviating pressure), the valve body 34 is pushed upward from the closing surface 32F against the biasing force of the coil spring 35, and a part of the air in the drive chamber B is discharged to the outside from the through hole 33H of the cover member 33.

  When the pressure in the driving chamber B falls below the predetermined value due to this discharge, the relief valve RV is closed again by the valve body 34, so that the abnormality of the vent 7A, the opening 15A or the air filter 17 continues. By repeating the collision sound generated between the valve body 34 and the closing surface 32F, the abnormality of the vent 7A, the opening 15A or the air filter 17 is indicated.

  Note that, based on the position adjustment along the axis X of the cover member 33, the threshold value of the pressure at which the relief valve RV is opened may be configured to be changeable. For example, by providing the cover member 33 in a form that is screwed into a female screw formed on the inner surface of the cylindrical main body 32, the cover member 33 is moved along the axis X based on a rotation operation from the outside of the cover member 33. Position adjustment.

Even in the case of a vacuum pump in which the piston ring 30 having the action of moving part of the air in the negative pressure chamber A to the drive chamber B when the piston 2 moves to the exhaust side is omitted, the relief valve RV (pressure The effect of the release mechanism is obtained.
That is, even in the vacuum pump in which the piston ring 30 is omitted, the tendency of the pressure in the driving chamber B to increase due to the movement of the piston 2 toward the intake side is remarkably based on the abnormality of the vent 7A, the opening 15A or the air filter 17. Become.

  The vacuum pump of FIG. 1 is described as a pressure release mechanism having a relief valve RV and a relay exhaust hose 9 at the same time. However, both of these may be provided at the same time. It is good also as a form provided only with one side.

(Compression pump)
The casing 21 shown in FIG. 1 is changed to another casing 21 in which a tube 25 communicating with an external object is connected to an exhaust space 21B of the casing 21 and a protruding portion 26 is communicated with an intake space 21A. Can be used as a compression pump (an example of a gas pump).

The relay exhaust hose 9 may be omitted to allow outside air to be sucked from the first pipe part 26, and the second pipe part 16 protruding from the silencer chamber S may be closed.
Instead of omitting the piston ring 30, an open / close valve (not shown) that opens when the piston 2 moves toward the intake side and closes when the piston 2 moves toward the exhaust side may be provided in the piston head of the piston 2 or the like. .

When used as a compression pump, if there is an abnormality in the vent 7A, the opening 15A or the air filter 17, the pressure in the driving chamber B is abnormal due to repeated movement of the piston 2 to the exhaust side (leftward in FIG. 1). If the pressure is lowered, the reciprocating drive of the piston 2 may be affected.
Therefore, instead of the relief valve RV, the pressure release hole 3H shown in FIG. 1 is released when the pressure in the drive chamber B falls below a predetermined lower limit value lower than the atmospheric pressure, and the outside air is supplied to the drive chamber B. A relief valve (not shown) of a negative pressure operation type that sucks in can be attached as a pressure release mechanism.

[Third Embodiment]
In the vacuum pump shown in FIG. 5, when the pressure in the drive chamber B or the silencer chamber S deviates from a predetermined range, the pressure release mechanism that adjusts the deviated pressure includes a first pipe portion 36 that communicates with the drive chamber B; The second pipe part 37 that communicates with the silencer chamber S, and the external relay hose 40 that connects the first pipe part 36 and the second pipe part 37 outside the drive chamber B are configured.

  The value of the internal pressure in the driving chamber B required for forcibly disconnecting the one end 40A of the external relay hose 40 from the first pipe portion 36 is the same as that of the other end 40B of the external relay hose 40 being forced from the second pipe portion 37. In order to be sufficiently higher than the value of the internal pressure of the silencer chamber S required for the connection to be released, a retainer 36A having an annular diameter is formed only at the tip of the first pipe portion 36.

  If there is no abnormality in the vent 7A, the opening 15A or the air filter 17, the first pipe portion 36 and the second pipe portion 37 are connected to each other by the external relay hose 40, and the piston 2 moves to the intake side. The air in the drive chamber B enters the silencer chamber S via the external relay hose 40 rather than the narrow vent 7A, and is discharged to the outside through the open port 15A.

  Therefore, the drive chamber B and the silencer chamber S are less likely to become high pressure due to the movement of the piston 2 toward the intake side, compared to the configuration in FIG. Therefore, the energy required for the reciprocating movement of the piston 2 can be reduced.

  When an abnormality occurs in the opening 15A or the air filter 17, the driving chamber B and the silencer chamber S increase in pressure due to repeated movement of the piston 2 to the intake side, but the internal pressure of the silencer chamber S exceeds a predetermined value. And the other end 40B of the external relay hose 40 is forcibly disconnected from the second pipe portion 37 by the deviating pressure. Thereafter, the exhaust from the negative pressure chamber A due to the movement of the piston 2 to the exhaust side is directly exhausted to the outside from the external relay hose 40 without passing through the silencer chamber S. By directly leaking into the air outlet, abnormality of the opening 15A or the air filter 17 is indicated.

Even in the case of a vacuum pump in which the piston ring 30 having the action of moving part of the air in the negative pressure chamber A to the drive chamber B when the piston 2 moves to the exhaust side is omitted, the external relay hose 40 ( The effect of the pressure release mechanism is obtained.
That is, even in the vacuum pump in which the piston ring 30 is omitted, the tendency of the pressure in the driving chamber B to increase due to the movement of the piston 2 toward the intake side is remarkably based on the abnormality of the vent 7A, the opening 15A or the air filter 17. Become.

  Since the first tube portion 36 and the second tube portion 37 are arranged in parallel so as to be generally in the same direction, the external relay hose 40 is inevitably curved in the vicinity of the intermediate portion or the like. In addition, the second pipe portions 26 and 16 are connected to each other, and the other end of the relay exhaust hose 9 is more reliably disconnected from the second pipe portion 37 by the excessive internal pressure of the silencer chamber S.

  The present invention includes a piston inside a cylinder so as to freely reciprocate, a pressure operation chamber on the cylinder head side, and a drive chamber that transmits a reciprocating driving force to the piston on the opposite side of the pressure operation chamber. Accordingly, the present invention can be used as a technique for solving a problem found in a gas pump including a valve unit that controls supply and discharge of gas to and from a pressure operation chamber.

1 cylinder 2 piston 2G annular groove 2T communication hole 3H pressure release hole (pressure release mechanism)
7A Vent 9 Relay exhaust hose (pressure release mechanism)
15A Opening port 17 Air filter 23 Exhaust valve 30 Piston ring 34 Valve element (closing means, pressure release mechanism)
36 1st pipe part 37 2nd pipe part 40 External relay hose (pressure release mechanism)
40A One end 40B The other end A Negative pressure chamber (pressure operation chamber)
B Drive chamber E First exhaust path F Second exhaust path G Merge space RV Relief valve (pressure release mechanism)
S Silencer chamber (exhaust part)
V valve unit

Claims (8)

A piston is provided inside the cylinder so as to be able to reciprocate freely, a pressure operation chamber is provided on the cylinder head side, and a drive chamber is provided on the opposite side of the pressure operation chamber to transmit the reciprocating drive force to the piston. A valve unit for controlling supply and discharge of gas to and from the pressure operation chamber,
A silencer chamber is provided as an exhaust part for exhausting the exhaust discharged from the valve unit to the outside of the device,
A pressure release mechanism is provided for adjusting the deviated pressure when the pressure in the driving chamber or the silencer chamber deviates from a predetermined range ;
The pressure operation chamber constitutes a negative pressure chamber;
The pressure release mechanism includes a first pipe part communicating with the valve unit, a second pipe part communicating with the silencer chamber, and the first pipe part and the second pipe part outside the negative pressure chamber. A gas pump comprising a hose that is connected and has one end disconnected from the first pipe part or the second pipe part by an excessive internal pressure of the silencer chamber . A coupling force between the one end and the first tubular portion of the hose, the coupling force between the other end and said second tubular portion of the hose, to claim 1, which is configured differently from each other The described gas pump. The gas pump according to claim 1 or 2 , wherein the first pipe part and the second pipe part are arranged facing each other. The gas pump according to any one of claims 1 to 3 , wherein the hose is bent and disposed. The pressure release mechanism closes the pressure release hole so that at least one of the drive chamber and the silencer chamber communicates with the outside, and the pressure release hole is temporarily disengaged by the deviated pressure. The gas pump according to claim 1, further comprising a closing means. The gas pump according to any one of claims 1 to 5 , wherein a vent hole is provided in the drive chamber for sending gas inside the drive chamber to the silencer chamber in response to an operation of the piston in an intake direction. . The pressure operation chamber constitutes a negative pressure chamber;
The pressure release mechanism connects the first tube portion communicating with the drive chamber, the second tube portion communicating with the silencer chamber, and the first tube portion and the second tube portion outside the drive chamber. The gas pump according to claim 6 , wherein one end is constituted by a hose that is disconnected from the first pipe part or the second pipe part by an excessive internal pressure of the drive chamber or the silencer chamber. . A coupling force between the one end and the first tubular portion of the hose, to claim 7 coupling force and is configured to be different from each other between the other end and said second tubular portion of said hose The described gas pump.

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