JP3138793B2 - Vacuum tank for negative pressure booster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum tank for a negative pressure booster for operating a negative pressure booster of a vehicle braking system.

[0002]

2. Description of the Related Art Normally, a negative pressure booster of a braking device of an automobile is operated by utilizing an intake negative pressure of an internal combustion engine. Since a negative pressure cannot be used, a vacuum tank connected to a vacuum pump unit including a motor and a vacuum pump is required.

As a vacuum tank for such a negative pressure booster,
The one described in JP-A-1-119467 is known.

[0004]

When manufacturing the vacuum tank for the negative pressure booster, it is desirable to reduce the manufacturing cost as much as possible.

The present invention has been made in view of the above circumstances, and has as its object to manufacture a vacuum tank for a negative pressure booster at low cost.

[0006]

According to one aspect of the present invention, there is provided a vacuum tank shell for operating a negative pressure booster connected to a vacuum pump unit comprising a motor and a vacuum pump. Is characterized by using a semi-finished product of the shell of the negative pressure booster.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the vacuum pump unit is mounted by using a master cylinder mounting portion provided at a front portion of a shell of the negative pressure booster. It is characterized by having.

According to a third aspect of the present invention, in addition to the configuration of the first aspect, a control unit for controlling the operation of the prime mover is provided in a rear extension cylinder projecting from a rear portion of a shell of the negative pressure booster. It is characterized by being stored.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 6 show a first embodiment of the present invention. FIG. 1 is a perspective view of a main part of an electric vehicle, FIG. 2 is a longitudinal sectional view of a negative pressure booster, and FIG. Longitudinal section, FIG. 4
3 is an enlarged view of a main part of FIG. 3, FIG. 5 is a sectional view taken along line 5-5 of FIG. 4, and FIG. 6 is a sectional view taken along line 6-6 of FIG.

First, in FIG. 1, an electric vehicle running by using an electric motor (not shown) as a drive source is provided with a master cylinder 2 for generating a brake hydraulic pressure for operating brake calipers 1 and 1 provided on wheels. A negative pressure booster 4 is provided between the brake pedal 3 and the master cylinder 2 for boosting the pedaling force of the brake pedal 3 and transmitting the boosted force to the master cylinder 2. The negative pressure booster 4 includes an electric motor 5 and a vacuum. A vacuum pump unit 7 composed of a pump 6 is connected to a vacuum tank 8 provided integrally.

As shown in FIG. 2, the shell 11 of the negative pressure booster 4 comprises a pair of front and rear shell halves 11a and 11b whose opposite ends are connected to each other. It is movably accommodated. A diaphragm 13 is superimposed on the rear surface of the booster piston 12. The outer bead 13a of the diaphragm 13 is connected to a groove 14 formed at the abutting portion of the two shell halves 11a and 11b, and the inner bead 13b of the diaphragm 13 is
The inner periphery of the booster piston 12 is coupled to the front periphery of the piston boss 15. The inside of the shell 11 is partitioned by the booster piston 12 and the diaphragm 13 into a front negative pressure chamber A facing the front surface of the booster piston 12 and a rear working chamber B facing the rear surface of the diaphragm 13.

At the center of the rear wall of the shell 11, a rear extension cylinder 16 for supporting the piston boss 15 slidably back and forth is integrally formed. A joint 17 is connected to the front wall of the shell 11, and the negative pressure chamber A communicates with the vacuum tank 8 as a negative pressure source via the joint 17. Brake pedal P3
The input rod 18 that is connected and moves back and forth has a spherical portion at the tip, and the spherical portion is pivotally supported by the rear end of a valve piston 19 fitted to the center of the piston boss 15 so as to swing. A stopper support member 20 is fixed to the input rod 18 by a lock nut 21 so as to be adjustable in position. The stopper member 20 is in contact with the rear end of the rear extension cylinder 16 to regulate the retreat end of the input rod 18. 22 are supported. Further, filters 23 are mounted between the piston boss 15 and the stopper support member 20 so as to purify the air introduced from the air introduction port 16a opened at the rear end of the rear extension cylinder 16.

The control valve V housed inside the piston boss 15 switches according to the relative movement between the valve piston 19 and the piston boss 15 due to the forward and backward movement of the input rod 18. That is, when the control valve V is in the switching neutral state, the valve piston 1
When the piston 9 moves forward with respect to the piston boss 15, the control valve V allows the working chamber B to communicate with the atmosphere through the atmosphere introducing port 16 a at the rear end of the rearward extension cylinder 16, so that the negative pressure chamber A and the working chamber B The booster piston 12 advances with the piston boss 15 due to the pressure difference therebetween. When the valve piston 19 moves backward with respect to the piston boss 15, the working chamber B is cut off from the atmosphere and communicates with the negative pressure chamber A so that the pressure difference disappears. 12 retracts with the piston boss 15.

A master cylinder mounting portion 25 provided on the front wall of the shell 11 has a cylinder body 26 of the master cylinder 2 attached thereto.
The mounting flange 26a formed in the above is fixed by a bolt 27 and a nut 28. An output rod 30 protruding forward from an output piston 29 supported on the front end of the piston boss 15 is provided.
It is connected to the working piston 31 of the master cylinder 2 through a through hole 25 a formed in the master cylinder mounting portion 25.

The negative pressure booster 4 having the above-described structure is provided with a bolt 3 penetrating the rear wall of the shell 11 and the vehicle body panel 32.
It is fixed to the vehicle body panel 32 by the nut 3 and the nut 34.

Thus, the depression force of the brake pedal 3 is boosted by the differential pressure between the negative pressure acting on the negative pressure chamber A by the vacuum pump unit 7 and the atmospheric pressure acting on the working chamber B, so that the master cylinder 2 is moved. Can be activated.

As shown in FIG. 3, the vacuum pump unit 7
Is integrally provided with a pair of front and rear shell halves 11 a ′ and 11 b ′ connected via a seal member 41.
Is provided. The shell 11 ′ of the vacuum tank 8 is composed of a semi-finished product of the shell 11 of the negative pressure booster 4. That is, the front shell half 11a 'is a semi-finished product before forming the through-hole 25a (see FIG. 2) of the front shell half 11a of the negative pressure booster 4, and the rear shell half 11b' is a negative pressure. This is a semi-finished product before forming the air inlet 16a (see FIG. 2) of the rear shell half 11b of the booster 4. A negative pressure booster 4 is provided on the front shell half 11a '.
1 corresponding to the joint 17 of the front shell half 11a of FIG.
7 'is provided, and both joints 17, 17'
2 are interconnected.

A mounting flange 43a provided on a pump housing 43 of the vacuum pump 6 is connected to a vacuum pump unit mounting portion 25 'of the front shell half 11a' by bolts 27 'and nuts 28'. The vacuum pump unit mounting portion 25 ′ of the front shell half 11 a ′ corresponds to the master cylinder mounting portion 25 of the front shell half 11 a of the negative pressure booster 4, and therefore, the front shell half of the negative pressure booster 4. Body 1
The vacuum pump unit 7 can be attached to the front shell half 11a 'of the vacuum tank 8 in the same manner as the method of attaching the master cylinder 2 to 1a.

The vacuum tank 8 is fixed to the vehicle body panel 32 by bolts 33 'and nuts 34' penetrating the rear wall of the shell 11 'and the vehicle body panel 32.

As shown in FIGS. 4 to 6, the pump housing 43 has an electric motor 5 connected to the front surface thereof by bolts 44 and a rear opening thereof is closed by a cover 46 fixed by bolts 45. . A pump chamber 47 having a cylindrical shape is formed inside the pump housing 43. A pump shaft 51 supported by a pair of ball bearings 48 and 49 and coupled to an output shaft 50 of the electric motor 5 includes:
A cylindrical pump rotor 52 is fixed.

The pump shaft 51 is located on the center line of the pump chamber 47, and the pump rotor 52 is eccentrically supported with respect to the pump shaft 51. The outer periphery of the pump rotor 52 farthest from the pump shaft 51 is in airtight sliding contact with the inner periphery of the pump chamber 47. A vane 54 is slidably fitted in a vane guide groove 53 extending radially outward from the pump chamber 47, and is urged toward the outer periphery of the pump rotor 52 by two springs 55, 55.

The pump housing 53 is formed with a discharge port 56 and a suction port 57 which open to the pump chamber 47. The discharge port 56 has an exhaust pipe 58 which opens to the atmosphere.
And a hose 59 is provided in the suction port 57.
A joint 61 is provided which communicates with the joint 60 (see FIG. 3) of the vacuum tank 8 via the.

When the electric motor 5 rotates the pump shaft 51 of the vacuum pump 6, the volume of the pair of working chambers 62 and 63 defined by the pump chamber 47, the pump rotor 52, and the vane 54 is increased. The air is reduced, and the air sucked from the suction port 57 is discharged from the discharge port 56 to the atmosphere. Thereby, the inside of the vacuum tank 8 connected to the vacuum pump 6 is depressurized, and the negative pressure booster 4 can be operated by the negative pressure.

As described above, since the shell 11 'of the vacuum tank 8 for operating the negative pressure booster 4 is formed by using a semi-finished product of the shell 11 of the negative pressure booster 4, a shell dedicated to the vacuum tank 8 is provided. There is no need to design and manufacture, and significant cost reductions are possible. In addition, since the vacuum pump unit 7 is mounted using the master cylinder mounting portion 25 for mounting the master cylinder 2 to the negative pressure booster 4, a special member for mounting the vacuum pump unit 7 becomes unnecessary, and the number of parts is reduced. Reduction is possible.

FIG. 7 shows a second embodiment of the present invention.
This second embodiment shows a rear shell half 11 of a shell 11 '.
A cylindrical control unit 64 having a pressure sensor for detecting the internal pressure of the vacuum tank 8, a CPU, a relay, and the like is housed in the rear extension cylinder 16 of a '. The front end of the control unit 64 is locked to the inner surface of the rear extension tube 16 by a clip 65, and the rear end of the control unit 64 passes through the air inlet 16a through the sealing member 66 so as not to impair the airtightness of the vacuum tank 8. The switch 67 and the battery 68 are connected thereto.

When the internal pressure of the vacuum tank 8 exceeds a predetermined value due to the operation of the negative pressure booster 4, the control unit 64 drives the electric motor 5 to operate the vacuum pump 6,
The internal pressure of the vacuum tank 8 is reduced.

According to this embodiment, the control unit 64 can be stored compactly by using the rear extension cylinder 16 of the shell 11 '.

FIG. 8 shows a third embodiment of the present invention.
In the third embodiment, a vacuum pump unit 7 is connected to a vacuum tank 8.
But mounted at an appropriate position near the vacuum tank 8. Thus, the vacuum pump unit 7
And the vacuum tank 8 are configured separately, so that the degree of freedom in layout can be increased.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made.

For example, in the embodiment, the shell 11 of the negative pressure booster 4 and the shell 11 'of the vacuum tank 8 are of the same type, but they need not necessarily be of the same type. In short, the shell 1 of the vacuum tank 8
1 'may be configured using a semi-finished product of the shell 11 of the negative pressure booster 4 of any model. Further, in the embodiment, the vacuum tank 8 is mounted on the electric vehicle, but the present invention can be applied to a vehicle using an internal combustion engine as a driving source for traveling.

[0032]

As described above, according to the first aspect of the present invention, the shell for the vacuum tank is designed using a semi-finished product of the shell for the negative pressure booster, thereby designing a shell dedicated to the vacuum tank. -It is not necessary to manufacture, and the cost can be reduced.

According to the second aspect of the present invention, since the vacuum pump unit is mounted using the master cylinder mounting portion provided at the front of the shell, no special mounting means is required. The vacuum pump unit can be easily attached.

According to the third aspect of the present invention, since the control unit for controlling the operation of the prime mover is housed in the rear extension cylinder projecting to the rear of the shell, the internal space of the rear extension cylinder 16 is reduced. By utilizing this, the control unit can be laid out compactly.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of an electric vehicle.

FIG. 2 is a longitudinal sectional view of a negative pressure booster.

FIG. 3 is a longitudinal sectional view of a vacuum tank.

FIG. 4 is an enlarged view of a main part of FIG. 3;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 4;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 4;

FIG. 7 corresponds to FIG. 3 according to a second embodiment of the present invention.

FIG. 8 is a view corresponding to FIG. 1 according to a third embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 4 Negative pressure booster 5 Electric motor (motor) 6 Vacuum pump 7 Vacuum pump unit 8 Vacuum tank 11 Shell 11 'Shell 16 Rear extension cylinder 25 Master cylinder mounting part 64 Control unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B60T 17/00-17/02 B60T 13/56

Claims (3)

(57) [Claims] 1. A shell (1) of a vacuum tank (8) connected to a vacuum pump unit (7) comprising a motor (5) and a vacuum pump (6) to operate a negative pressure booster (4).
1 ') using a semi-finished product of the shell (11) of the negative pressure booster (4). 2. The vacuum pump unit (7) is mounted using a master cylinder mounting part (25) provided at a front part of a shell (11) of the negative pressure booster (4). The vacuum tank for a negative pressure booster according to claim 1. 3. A control unit (64) for controlling the operation of the prime mover (5) is housed in a rear extension cylinder (16) projecting from a rear part of a shell (11) of the negative pressure booster (4). The vacuum tank for a negative pressure booster according to claim 1, wherein: