JP2016138506A - Vacuum pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum pump free from the deterioration of working efficiency without sucking air from an atmosphere communication hole during operation.SOLUTION: A vacuum pump 1 which includes a rotor 3, a vane to be rotated together with the rotor 3, and a housing storing the rotor 3 and the vane, sucks air through contraction or enlargement of a plurality of working spaces that the vane divides. The vacuum pump is provided with a lubricating oil passage 11 communicated with the inside of the housing and an atmosphere communication hole 13 communicated with the inside of the housing. It further includes a valve mechanism 20 for closing either the lubricating oil passage 11 or the atmosphere communication hole 13, the valve mechanism 20 serving for closing the lubricating oil passage 11 and opening the atmosphere communication hole 13 when a lubricating oil pressure is being low, and for opening the lubricating oil passage 11 and closing the atmosphere communication hole when the lubricating oil pressure is being high.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a vacuum pump technology.

  Conventionally, a vacuum pump that functions as a negative pressure source is known (see Patent Document 1). Such a vacuum pump includes a rotor, a vane that rotates together with the rotor, and a housing that houses the rotor and the vane. The vacuum pump sucks air by contracting or expanding a plurality of working spaces partitioned by the vanes.

  Incidentally, the vacuum pump described in Patent Document 1 is provided with a lubricating oil passage connected to the inside of the housing in order to lubricate the inside of the housing during operation. Further, the vacuum pump described in Patent Document 1 is provided with an air communication hole connected to the inside of the housing in order to prevent the lubricating oil from accumulating inside the housing at the time of stopping. However, such a vacuum pump sucks air from the air communication hole during operation, and has a problem that the operation efficiency is lowered.

JP 2012-67730 A

  Provided is a vacuum pump in which air is not sucked from an air communication hole during operation and operation efficiency is not lowered.

The first invention is
A rotor,
A vane that rotates with the rotor;
A housing for housing the rotor and the vane,
In the vacuum pump that sucks air by contracting or expanding each of a plurality of working spaces defined by the vanes,
A lubricating oil passage leading to the interior of the housing;
Providing an air communication hole connected to the inside of the housing,
A valve mechanism for closing either the lubricating oil passage or the air communication hole;
The valve mechanism closes the lubricating oil passage when the lubricating oil pressure is low and opens the atmospheric communication hole, and opens the lubricating oil passage when the lubricating oil pressure is high and opens the atmospheric communication hole. It is said to block.

The second invention is a vacuum pump according to the first invention,
The valve mechanism is
A valve housed in a sleeve formed in the rotor;
A spring that urges the valve in a state of being accommodated in the sleeve,
The lubricating oil passage and the air communication hole are connected to the sleeve,
The valve is pushed by the spring when the lubricating oil pressure is low and slides in one direction so as to block the lubricating oil passage and open the air communication hole, and lubricate when the lubricating oil pressure is high. In order to slide to the other side when pushed by oil, the lubricating oil passage is opened and the atmospheric communication hole is closed.

A third invention is a vacuum pump according to the second invention,
The valve is based on the state in which the lubricating oil passage is closed and the atmospheric communication hole is opened, and when the lubricating oil pressure is increased, the lubricating oil passage is opened and the atmospheric communication hole is closed. Is.

  Since the vacuum pump to which the technical idea of the present invention is applied does not suck air from the air communication hole during operation, the operation efficiency does not decrease.

It is a figure which shows the vacuum pump which concerns on one Embodiment of this invention. It is a figure which shows the AA cross section. It is a figure which shows a valve mechanism. It is a figure which shows the operation | movement aspect of a valve mechanism. It is a figure which shows the flow of the air at the time of a stop. It is a figure which shows the flow of the lubricating oil at the time of operation.

  With reference to FIG. 1 and FIG. 2, the vacuum pump which concerns on one Embodiment of this invention is demonstrated. The vacuum pump 1 is fixed to the side surface of the engine, for example, and functions as a negative pressure source such as a brake booster.

  The vacuum pump 1 includes a housing 2 having an elliptical pump chamber 2A, a rotor 3 disposed in the pump chamber 2A and pivotally supported at a position eccentric to the center of the pump chamber 2A, and the pump chamber 2A And a cover 5 that closes the opening of the large-diameter portion 2B in the housing 2, that is, the opening of the pump chamber 2A.

  The housing 2 has a large-diameter portion 2B whose inside is the pump chamber 2A, a medium-diameter portion 2C formed adjacent to the large-diameter portion 2B, and a small-diameter portion 2D formed adjacent to the medium-diameter portion 2C. It is equipped with. The large-diameter portion 2B accommodates the vane 4 in a rotatable manner. The medium diameter portion 2C and the small diameter portion 2D pivotally support the rotor 3. The large diameter portion 2B is provided with a suction passage 6 for sucking air from the brake booster to the pump chamber 2A. A check valve is provided upstream of the suction passage 6 in order to maintain the negative pressure of the brake booster. Further, a discharge passage 7 for pushing air out from the pump chamber 2A is provided in the medium diameter portion 2C. The housing 2 is provided with a reed valve 8 that opens and closes the discharge passage 7 when necessary.

  The rotor 3 has a guide groove 3A in the diameter direction formed at one end thereof. The guide groove 3A supports the plate-like vane 4 so as to be slidable in the diametrical direction. Caps 4 </ b> A and 4 </ b> A that are in contact with the inner peripheral surface of the pump chamber 2 </ b> A are attached to the tip of the vane 4. When the vane 4 rotates, the caps 4A and 4A slide while maintaining airtightness with the inner peripheral surface of the pump chamber 2A. Further, when the vane 4 rotates, the side surfaces 4B and 4B of the vane 4 slide while maintaining airtightness with the inner wall surface of the cover 5 or the inner wall surface of the pump chamber 2A. In addition, as for the rotor 3, a part of outer peripheral surface is in contact with the inner peripheral surface of 2 A of pump chambers (refer the point X of FIG. 1). Therefore, the pump chamber 2A is divided into three working spaces 2a to 2c. The working spaces 2a to 2c contract or expand as the vane 4 rotates. More specifically, the positive pressure chamber 2a, the negative pressure chamber 2b, and the compression chamber 2c, which are working spaces, contract or expand as the vane 4 rotates.

  With such a structure, when the rotor 3 rotates in conjunction with the engine, the vane 4 also rotates together with the rotor 3. Then, the air in the brake booster is sucked into the negative pressure chamber 2 b through the suction passage 6. At the same time, the air in the positive pressure chamber 2 a is discharged to the outside through the discharge passage 7. In this way, the vacuum pump 1 functions as a negative pressure source by continuously repeating suction and discharge of air.

  In addition, the vacuum pump 1 is provided with a lubricating oil passage 11 connected to the inside of the housing 2 (see FIG. 3). That is, the vacuum pump 1 is provided with the lubricating oil passage 11 connected to the pump chamber 2A. The lubricating oil passage 11 is configured by combining a plurality of passages. In the vacuum pump 1, the valve mechanism 20 is disposed in a part of the lubricating oil passage 11. The lubricating oil is supplied to the valve mechanism 20 through the passage 3B after passing through the oil supply pipe 12. Thereafter, the lubricating oil is supplied to the pump chamber 2A through the passage 3C and the passage 2E after passing through the valve mechanism 20 on condition that the valve mechanism 20 is in a predetermined operation state (arrow Fo in FIG. 6). reference).

  In addition, the vacuum pump 1 is provided with an air communication hole 13 connected to the inside of the housing 2 (see FIG. 3). That is, the vacuum pump 1 is provided with an air communication hole 13 connected to the pump chamber 2A. The atmosphere communication hole 13 is configured by combining a plurality of passages. In the vacuum pump 1, the valve mechanism 20 is disposed in a part of the air communication hole 13. The air is supplied to the valve mechanism 20 through the passage 3C after passing through the passage 2F. Thereafter, the air is supplied to the pump chamber 2A through the passage 3C and the passage 2E after passing through the valve mechanism 20 on condition that the valve mechanism 20 is in a predetermined operating state (see arrow Fa in FIG. 5). ).

  Next, the valve mechanism 20 will be described in detail with reference to FIGS. 3 and 4. The valve mechanism 20 changes its operating state according to the lubricating oil pressure, and changes the flow of the lubricating oil and air.

  The valve mechanism 20 includes a valve 21 and a spring 22 that biases the valve 21.

  The valve 21 is disposed inside a sleeve 3S formed on the rotor 3 and is slidable. Further, the spring 22 biases the valve 21 in a state where the spring 22 is disposed inside the sleeve 3S. The valve 21 is formed with an oil hole 21A penetrating from one end surface to the outer peripheral surface. The oil hole 21 </ b> A is formed at a position where the inlet portion is eccentric with respect to the passage 3 </ b> B constituting the lubricating oil passage 11. The outlet of the oil hole 21 </ b> A is formed on the outer peripheral surface of the valve 21. In the valve mechanism 20, the sleeve 3 </ b> S is a space provided in the rotor 3. However, a barrel that can accommodate the valve 21 and the spring 22 may be provided, and the barrel may be inserted into the rotor 3.

  With such a structure, the operating state of the valve mechanism 20 is switched according to the lubricating oil pressure. More specifically, when the lubricating oil pressure is low, the valve 21 slides in one direction by the biasing force of the spring 22, so that the valve 21 closes the lubricating oil passage 11 ((A) in FIG. 4). reference). At this time, the air communication hole 13 communicates with the passage 3 </ b> C connected on the upstream side and the downstream side of the valve 21. Accordingly, the lubricating oil does not flow downstream from the valve mechanism 20, but air flows downstream from the valve mechanism 20. That is, only air can flow to the pump chamber 2A (see arrow Fa in FIG. 5). On the contrary, when the lubricating oil pressure is high, the valve 21 slides to the other side against the urging force of the spring 22, so that the valve 21 closes the atmosphere communication hole 13 ((B) of FIG. 4). reference). At this time, the lubricating oil passage 11 is in communication with the passage 3B, the oil hole 21A, and the passage 3C. Accordingly, air does not flow downstream from the valve mechanism 20, but lubricating oil flows downstream from the valve mechanism 20. That is, only the lubricating oil can flow to the pump chamber 2A (see arrow Fo in FIG. 6).

  Below, it demonstrates based on the driving | running state of an engine.

  When the engine is stopped from the operating state, the hydraulic pump of the engine is also stopped. Therefore, the lubricating oil sent to the vacuum pump 1 is in a low pressure state. Accordingly, the valve 21 is slid to one side by the urging force of the spring 22 and closes the lubricating oil passage 11 (see FIG. 4A). At this time, since the air communication hole 13 is in communication, only the air is sucked into the pump chamber 2A by the negative pressure of the negative pressure chamber 2b (see arrow Fa in FIG. 5). Therefore, the lubricating oil does not accumulate in the pump chamber 2A.

  When operating from a state where the engine is stopped, the hydraulic pump of the engine is also operated. Therefore, the lubricating oil sent to the vacuum pump 1 is in a high pressure state. Then, the valve 21 slides to the other side against the urging force of the spring 22 and closes the atmosphere communication hole 13 (see FIG. 4B). At this time, since the lubricating oil passage 11 is in communication, only lubricating oil is supplied into the pump chamber 2A (see arrow Fo in FIG. 6). Therefore, the inside of the pump chamber 2A can be lubricated.

  As described above, since the vacuum pump 1 does not suck air from the atmosphere communication hole 13 during operation, the operating efficiency does not decrease. Moreover, since this vacuum pump 1 has little discharge loss of air, it can reduce operating resistance. Further, since the vacuum pump 1 does not suck in air from the air communication hole 13 during operation, it also has an effect of reducing air discharge noise.

DESCRIPTION OF SYMBOLS 1 Vacuum pump 2 Housing 2a Working space 2b Working space 2c Working space 3 Rotor 3S Sleeve 4 Vane 11 Lubricating oil passage 13 Atmospheric communication hole 20 Valve mechanism 21 Valve 22 Spring

Claims (3)

A rotor,
A vane that rotates with the rotor;
A housing for housing the rotor and the vane,
In the vacuum pump that sucks air by contracting or expanding each of a plurality of working spaces defined by the vanes,
A lubricating oil passage leading to the interior of the housing;
Providing an air communication hole connected to the inside of the housing,
A valve mechanism for closing either the lubricating oil passage or the air communication hole;
The valve mechanism closes the lubricating oil passage when the lubricating oil pressure is low and opens the atmospheric communication hole, and opens the lubricating oil passage when the lubricating oil pressure is high and opens the atmospheric communication hole. Vacuum pump characterized by blocking. The valve mechanism is
A valve housed in a sleeve formed in the rotor;
A spring that urges the valve in a state of being accommodated in the sleeve,
The lubricating oil passage and the air communication hole are connected to the sleeve,
The valve is pushed by the spring when the lubricating oil pressure is low and slides in one direction so as to block the lubricating oil passage and open the air communication hole, and lubricate when the lubricating oil pressure is high. 2. The vacuum pump according to claim 1, wherein the lubricating oil passage is opened so as to slide to the other side when pushed by oil, and the atmospheric communication hole is closed.   The valve is based on a state in which the lubricating oil passage is closed and the atmosphere communication hole is opened, and when the lubricating oil pressure becomes high, the lubricating oil passage is opened and the atmosphere communication hole is closed. The vacuum pump according to claim 2, wherein the vacuum pump is characterized.

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