JP2009257284A - Vacuum pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an auxiliary vacuum pump preventing heat effect on a component arranged near an exhaust port of a pump even when heat is generated. <P>SOLUTION: The auxiliary vacuum pump is driven by an electric motor to generate a negative pressure, is arranged together with a main vacuum pump 7, and has a smaller capacity in comparison to the main pump 7. A mounting surface 50R for mounting a pump 8 is formed on an outer side part. A suction port 40 of compressed air is provided on a surface different from the mounting surface 50R, and a discharge port 35 of air is provided on the mounting surface 50R. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vacuum pump used in a brake booster.

2. Description of the Related Art Conventionally, a brake device for a diesel vehicle such as a truck or a bus is known that uses a vacuum pump (vane vacuum pump) as a brake booster (see, for example, Patent Document 1).
Also, North American legislation stipulates that this brake device is provided with a brake assist device. Therefore, a vacuum pump that operates in an auxiliary manner may be provided when the main vacuum pump does not operate in order to comply with this law.

This auxiliary vacuum pump has a smaller compression capacity than the main vacuum pump, and is reduced in size and weight. The auxiliary vacuum pump is not supplied with power during normal operation and is driven with power supplied only when assisting the main vacuum pump.
JP 2008-75586 A

  As described above, the auxiliary vacuum pump is used only until the main vacuum pump is restored, and the time is preferably short. However, if it is necessary to operate for a long time before recovery, or if the necessity of recovery is not noticed, the auxiliary vacuum pump is energized for a long time and the compression capacity is small. The pump may generate heat. For this reason, the air discharged from the auxiliary vacuum pump becomes hot, and there is a risk of affecting the components disposed near the air discharge port.

  The present invention has been made in view of the above-described circumstances, and provides an auxiliary vacuum pump that is less likely to have a thermal effect on components arranged near the exhaust port of the pump even when heat is generated. Objective.

  In the present invention, a negative pressure is generated by being driven by an electric motor, and is provided together with a main vacuum pump. In an auxiliary vacuum pump having a smaller capacity than the main pump, a pump is provided on the outer side. A mounting surface for mounting is formed, and an air suction port is provided on a surface different from the mounting surface, while a compressed air discharge port is provided on the mounting surface.

  The pump is a vane type vacuum pump, and has an outer surface of the pump having a plurality of planes parallel to the axis of the rotary shaft, and one of the planes is the mounting surface, A crab suction port may be formed.

  Further, the plurality of planes may be four and have a substantially rectangular shape, and an angle from the suction port to the discharge port in the rotation direction of the vane pump may be about 270 degrees.

  According to the vacuum pump of the present invention, a mounting surface for mounting the pump is formed on the outer side, and a compressed air suction port is provided on a plane different from the mounting surface, while an air discharge port is provided on the mounting surface. Therefore, by discharging exhaust air having a high temperature to the mounting surface side, it is possible to make it difficult to exert a thermal effect on the components that are mounted on the portion that contacts the surface other than the mounting surface.

  The pump is a vane type vacuum pump, and has an outer surface of the pump having a plurality of planes parallel to the axis of the rotary shaft, and one of the planes is the mounting surface, Since the crab suction port is formed, exhaust air with high temperature is discharged to the mounting surface side, so that it can be mounted on a surface other than the mounting surface and in contact with another surface that is different in the rotation direction of the pump It is possible to make the part less susceptible to thermal influence.

  Further, the plurality of planes are four and have a substantially rectangular shape, and the angle from the suction port to the discharge port in the rotation direction of the vane pump is about 270 degrees. The function of compressing is not impaired.

Hereinafter, a vacuum pump according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a brake device using an auxiliary vacuum pump according to an embodiment of the present invention.
A brake device 100 used in a diesel vehicle such as a small truck or a bus includes front brakes 1a and 1b attached to left and right front wheels, and rear brakes 2a and 2b attached to left and right rear wheels. These brakes are connected to the master cylinder 3 by a brake pipe 9, and each brake is operated by hydraulic pressure sent from the master cylinder 3 through the brake pipe 9.
Further, the brake device 100 includes a brake booster 5 connected to the brake pedal 4 so that the pedaling force of the brake pedal 4 is reduced by the air pressure in the vacuum tank 6 and the piston (not shown) of the master cylinder 3 is moved. It has become.

The vacuum tank 6 is connected to a main vacuum pump 7 for discharging air. The main vacuum pump 7 operates during normal operation of the vehicle, and discharges air in the tank to the outside of the vehicle in order to make the vacuum tank 6 in a vacuum state. The brake booster 5, the vacuum tank 6, and the vacuum pump 7 are connected by an air pipe 10a.
Further, the vacuum pump 7 and the air pipe 10a are provided with a pressure sensor 28 and a control circuit 29, so that the pressure in the vacuum pump 7 can be checked to detect whether the vacuum pump 7 is operating abnormally. I am doing so.

  On the other hand, an auxiliary vacuum pump 8 is connected to the brake booster 5 via an air pipe 10b. The auxiliary vacuum pump 8 is supplied with power and operates when an abnormality of the main vacuum pump 7 is detected. The auxiliary vacuum pump 8 is used for auxiliary purposes, and has a smaller compression capacity than the main vacuum pump 7.

  Further, the auxiliary vacuum pump 8 is arranged utilizing the space above the vehicle body relative to the brake pedal 4 and the brake booster 5, as schematically shown in FIG. Therefore, it is desirable that the vacuum pump 8 has a small outer shape, and no cooling means or the like for cooling the inside of the vacuum pump 8 is provided, so that the size of the vacuum pump 8 is reduced. Specifically, the vacuum pump 8 is disposed behind the instrument panel (not shown) facing the driver's seat and in the vicinity of the air conditioner (not shown) exposed from the instrument panel. become. For this reason, a resin air conditioner duct (not shown) or the like is piped near the vacuum pump 8.

  FIG. 2 is a side view of the auxiliary vacuum pump 8 according to the embodiment of the present invention, and FIG. 3 is a cross-sectional view showing a state in which the vacuum pump 8 of FIG. 1 is cut along line AA. Furthermore, FIG. 4 shows a part of the pump in cross section in the side view of FIG. In the following description, the vertical and horizontal directions are based on FIG.

As shown in FIG. 2, the vacuum pump 8 has a central axis X extending in the left-right direction, and includes an electric motor 10 located on the right side, a vane pump 20 located on the left side, and between the electric motor 10 and the vane pump 20. And an intervening motor cover 30.
The electric motor 10 includes a motor case 11 that covers the outside thereof, and a rotating shaft 12 (see FIGS. 3 and 4) that is provided inside the motor case 11 and that can rotate around a central axis X. The rotary shaft 12 is rotationally driven by a rotor attached to the rotary shaft 12 and a stator attached to the motor case 11 so as to be spaced from the outer periphery of the rotor. .

  The motor case 11 has a substantially cylindrical shape with an open left side surface, and a flange portion 11b is formed on the opening edge portion so as to protrude outward from the outer peripheral surface 11a. The flange portion 11 b is fixed with the motor cover 30 and the bolt 15. A bearing (not shown) that supports the right end of the rotating shaft 12 is provided inside the right side of the motor case 11.

  The motor cover 30 is attached so as to close the left opening of the motor case 11. As shown in FIG. 4, the motor cover 30 is provided with a bearing 16 that pivotally supports the left side of the rotating shaft 12 at the center thereof. Thereby, the rotating shaft 12 is supported by the left and right bearings and is configured to be rotatable.

Further, as shown in FIG. 3, the motor cover 30 has an outer periphery formed in a substantially rectangular shape when viewed along the axis X, and has four planes (an upper surface 50U, a lower surface 50B, and a left surface). 50L and right surface 50R (mounting surface)) are formed.
A suction port 40 for sucking air is attached to the upper surface 50U of the motor cover 30. The suction port 40 protrudes upward and then bends toward the right side.
Further, a wiring 17 for controlling the electric motor 10 and supplying electric power extends from the lower surface 50 </ b> B of the motor cover 30.
Further, the right surface 50R of the motor cover 30 is used as an attachment surface, and two attachment portions 51 are formed as shown in FIG. The mounting portion 51 is formed with a mounting hole 52 that is threaded. As shown in FIG. 3, the attachment portion 51 is attached to the attachment member 53 on the vehicle body side with a fastening member such as a bolt 54. More specifically, the discharge port 53 is disposed so as to be covered by the mounting member 53.

Further, as shown in FIG. 4, an intake passage 32 is formed in the motor cover 30 at a portion above the rotating shaft 12. The intake passage 32 communicates with the intake port 40 in a state where the intake port 40 described above is attached. The intake passage 32 is located on the electric motor 10 side, and has a narrow passage 32a extending from the suction port 40 toward the lower side, and extends from the lower side of the passage 32a toward the inside of the vane pump 20. And a wide passage 32b having a large opening. As a result, the suction port 40 communicates with the inside of the vane pump 20 through the intake passage 32 and can send air.
In addition, a check valve (not shown) is provided inside the intake passage 32 so that the passage 32 can be controlled to be freely opened and closed.

  The vane pump 20 is a rotary vane-type vacuum pump, and as shown in FIGS. 3 and 4, a cylinder body 21 constituting the outer shape of the vane pump 20, a rotor 22 positioned inside the cylinder body 21, and a cylinder Plates 23 a and 23 b are provided at both left and right ends of the main body 21. Further, an outer plate 24 fastened to the cylinder body 21 with three bolts 34 is attached to the left side of the plate 23a.

As shown in FIGS. 3 and 4, the cylinder body 21 has a cylindrical shape with openings on the left and right sides, and an inner peripheral wall surface 21 a is formed along a central axis X extending in the left and right directions. In addition, as shown in FIG. 3, the cylinder body 21 is formed with an injection port 31 located on the upper left side with respect to the rotating shaft 12 and a discharge port 27 located on the lower right side.
The inlet 31 is an opening at the end of the intake passage 32 described above, and communicates with the suction port 40. Further, as shown in FIG. 3, the discharge port 27 communicates with an exhaust passage 33 that extends from the discharge port 27 toward the right side. Further, the discharge port 27 is disposed at an end portion on the opposite side of the exhaust passage 33. It communicates with the outlet 35. As shown in FIG. 2, the discharge port 35 is formed in a right surface 50R having a function as a mounting surface, and communicates with the atmosphere.

  The rotor 22 has a cylindrical shape having a central axis Y at a position eccentric from the central axis X. A driving force is transmitted to the rotor 22 via the rotary shaft 12 and the connection key 26. Further, as shown in FIG. 1, the plates 23 a and 23 b are assembled so as to block the openings at the left and right ends of the cylinder body 21 and leave no gap between the both ends of the rotor 22.

  Further, as shown in FIG. 2, the rotor 22 is provided with four vanes 25 that project obliquely toward the inner peripheral wall surface 21 a of the cylinder body 21. The vane 25 protrudes outward of the rotor 22 along a sliding groove 22b provided in the rotor 22 by a centrifugal force accompanying the rotation, and the tip of the vane 25 comes into contact with the inner peripheral wall surface 21a. The state of the vane 25 in FIG. 2 will be described in detail. The vane 25 located in the upper portion projects outward from the inside of the rotor 22, and the tip of the vane 25 contacts the inner peripheral wall surface 21 a of the cylinder body 21. It touches. On the other hand, the vane 25 positioned in the lower portion is pushed inward of the rotor 22 with its tip end abutting against the inner peripheral wall surface 21 a and is retracted into the rotor 22. With this structure, for example, when the rotor 22 rotates counterclockwise in FIG. 3, the pressure chamber P partitioned by the outer wall surface of the rotor 22, the inner peripheral wall surface 21 a of the cylinder body 21, and the adjacent vane 25 moves. Thus, air is sent from the injection port 31 (formed at a location where the volume of the pressure chamber P is large) to the discharge port 27 (formed at a location where the volume of the pressure chamber P is small).

  In such a vane type vacuum pump, the air in the pressure chamber P tends to become high temperature because the vane 25 and the inner peripheral wall surface 21a slide. Further, since the auxiliary vacuum pump 8 is not provided with a cooling mechanism in order to reduce the size as described above, the air in the pressure chamber P tends to be relatively hot.

  With this configuration, the air that has moved into the vane pump 20 from the upper suction port 40 in FIG. 3 is compressed in accordance with the change in the volume of the pressure chamber P, and from the discharge port 27 through the exhaust passage 31, 3 is discharged to the right outside (atmosphere). That is, the intake port 40 (or the intake passage 32) and the exhaust port 35 (or the exhaust passage 33) have an angle of about 270 degrees in the counterclockwise direction that is the rotation direction of the vane pump, as shown in FIG. The air entering from the suction port 40 rotates about 270 degrees in the vane pump and is discharged from the discharge port 35.

  According to the auxiliary vacuum pump 8 according to the embodiment of the present invention, the flat surface 50R which is a mounting surface for mounting the vacuum pump 8 is formed on the outer surface of the motor cover 30, and the upper surface 50U different from the flat surface 50R is formed. While the air suction port 40 is provided and the air discharge port 35 is provided on the flat surface 50R, exhaust air having a high temperature can be discharged to the flat surface 50R side as the mounting surface. For this reason, for example, high-temperature air is not blown toward a resin-made air-conditioner duct or the like piped in the vicinity of any of the upper surface 50U, the lower surface 50B, and the left surface 50L. Can be difficult to give. Further, components other than the air-conditioner duct that are easily affected by heat can be disposed in the vicinity of the vacuum pump 8.

  Further, the mounting member 53 on the vehicle body side that does not cause a problem even when the temperature becomes high is disposed so as to cover the exhaust port 35 so that the high-temperature exhaust gas discharged from the discharge port 35 is applied to the mounting member 53. , The flow can be moderated. Thereby, it can prevent that high temperature gas is sprayed directly on specific components, such as an air-conditioner duct. That is, when there is no mounting member 53 on the vehicle body side, the high-temperature exhaust gas can flow in one direction in which the discharge port 53 is open, but the mounting member 53 is directed by directing the discharge port 53 toward the mounting member 53. As a result, the high temperature exhaust gas diffuses along the surface, so that the high temperature exhaust gas is not sprayed only on specific parts.

  Further, since the angle from the suction port 40 to the discharge port 35 in the rotation direction of the vane type pump is about 270 degrees, the air can be sufficiently compressed by an angle of about 270 degrees, and the function of compressing the air can be achieved. No damage.

Although the best embodiment for carrying out the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications and changes can be made based on the technical idea of the present invention. It is.
For example, in the present embodiment, a vane type vacuum pump is used to compress air. However, if the suction port 40 and the discharge port 35 can be provided on different surfaces, the vane type pump is limited. Not.

  Further, four planes are formed in the motor cover 30 and the suction port 40 and the discharge port 35 are provided in these planes. However, if the planes can be provided on different planes, they are configured in a mode having three planes. It doesn't matter. Naturally, it may be configured in a form having five or more surfaces. That is, for example, when formed with N planes, it is preferable to form the discharge port 35 on the adjacent surface opposite to the rotation direction of the rotor 22 from the surface on which the suction port 40 is formed. By providing on such an adjacent surface, the compression efficiency of the vane type vacuum pump is not impaired.

  Furthermore, although the suction port 40 to the discharge port 35 are shifted by about 270 degrees with respect to the rotation direction, they may be 270 degrees or less as long as the air compression function can be secured. This angle can be freely determined from the viewpoint of ensuring the number of planes and the compression function described above.

It is a schematic diagram of a brake device provided with a vacuum pump concerning an embodiment of the invention. It is a side view of the vacuum pump concerning an embodiment of the invention. It is sectional drawing cut | disconnected by the AA line of FIG. It is a side view which shows the vane type vacuum pump of FIG. 2 in a cross section.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Front brake 2a Rear brake 3 Master cylinder 4 Brake pedal 5 Brake booster 6 Vacuum tank 7 Main vacuum pump 8 Auxiliary vacuum pump 9 Brake piping 10 Electric motor 10a, 10b Air piping 11 Motor case 11a Outer surface 11b Flange 11c Suction port 12 Rotating shaft 15 Bolt 16 Bearing 17 Wiring 20 Vane pump 21 Cylinder body 21a Inner peripheral wall surface 22 Rotor 22b Sliding groove 23a Plate 24 Outer plate 25 Vane 26 Connection key 27 Discharge port 28 Pressure sensor 29 Control circuit 30 Motor cover 31 Note Inlet 31 Seal ring 32 Intake passage 32, 32a, 32b Passage 33 Exhaust passage 34 Bolt 35 Discharge port 40 Suction port 50U Upper surface 50B Lower surface 50L Left surface 50R Right (Mounting surface)
51 mounting portion 52 mounting hole 53 mounting member on the vehicle body side 54 bolt 100 brake device P pressure chamber X central axis Y central axis

Claims (3)

In an auxiliary vacuum pump that is driven by an electric motor to generate a negative pressure and is provided together with a main vacuum pump and has a smaller capacity than the main pump.
A vacuum pump characterized in that a mounting surface for mounting the pump is formed on the outer side, an air suction port is provided on a surface different from the mounting surface, and a compressed air discharge port is provided on the mounting surface.   The pump is a vane-type vacuum pump, and has a plurality of planes parallel to the axis of the rotation shaft on the outer surface of the pump, and one of the planes is the mounting surface, The vacuum pump according to claim 1, wherein a suction port is formed.   The plurality of planes are four and have a substantially rectangular shape, and an angle from the suction port to the discharge port in the rotation direction of the vane pump is about 270 degrees. Vacuum pump.

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