JPH0765591B2 - Selective delivery pump - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a selective delivery pump, and more particularly, to selectively supply a washer fluid to a front window and a rear window of an automobile. The present invention relates to a selective delivery pump that selectively supplies liquid to two systems from one tank.

(Background Art) When supplying washer fluid to a front window and a rear window of an automobile, a washer fluid tank and a delivery pump are generally provided separately. However, if the cleaning devices are separately provided in this way, the space occupied by each cleaning device becomes large and the cost also increases.

In order to solve these problems, the applicant of the present invention has developed a selective delivery pump in which a single wash pump selectively delivers the washer fluid to two different cleaning systems from a common washer fluid tank. In this type of selective delivery pump, an impeller having a large number of recessed grooves is provided in a peripheral wall in a casing, and the impeller is connected to an output shaft of a forward / reverse motor, and the impeller is provided between the inner wall of the casing and the impeller. Forming a working passage for delivering a liquid by a pumping action due to rotation of an impeller, and providing two valve chambers, which are respectively connected to the working passage, adjacent to each other in the casing by partitioning the partition. Is provided with a liquid introduction path for introducing the liquid from the external tank, the suction ports communicating the liquid introduction path with the both valve chambers are opened in the partition walls, respectively, and the suction ports are opposed to the suction ports on the inner wall of the both valve chambers. And a valve rod having both ends projecting into the respective valve chambers by movably inserting the partition wall into the respective valve chambers, and at the both ends of the valve rod, when the valve rod moves, Open the inlet of the valve chamber of It is to the suction port of the other valve chamber closed, characterized by comprising a discharge port open and eggplant valve body fixedly mounted respectively when the outlet is closed.

This selective delivery pump selectively delivers liquid to the required location,
Moreover, it has an excellent effect in that it can be accurately transmitted.

The above-mentioned selective delivery pump has the same pump characteristics in forward and reverse rotation. However, automobile manufacturers demand that the discharge pressure on the rear window side be lower than that on the front window side.

This is because the discharge pressure on the front window side needs to be high so that it is not affected by the wind pressure when the vehicle is running.On the rear window side, if the tank of the washer liquid is installed in front of the vehicle, the piping is long and the pressure is high. There is a risk that the connection part of the hose may come off if the liquid is sent by. For this reason, it is uneconomical to feed the band to the connecting portion and to provide a decompression adjusting means, so that it is desired to develop a selective delivery pump having different discharge pressures.

(Means for Solving Problems) In order to solve the above problems, the present invention has the following configuration.

That is, an impeller having a large number of grooves or fins on the peripheral wall is provided in the casing, and the impeller is connected to the output shaft of the forward / reverse motor so that the impeller rotates between the inner wall of the casing and the impeller. To form a working passage for delivering a liquid by a pumping action, and in the casing, two valve chambers that respectively communicate with the working passage are provided adjacent to each other by partitioning the partition walls from each other. A liquid introduction path for introducing a liquid is provided, and suction ports communicating the liquid introduction path with the valve chambers are opened in the partition walls,
A valve rod is provided on the inner wall of the both valve chambers, the outlet being opened at a position facing each of the inlets, the partition wall being movably inserted, and both ends protruding into the valve chamber. A valve element that opens the inlet of one valve chamber and closes the inlet of the other valve chamber when the valve rod moves and closes the outlet of the other valve chamber when the valve rod moves. In each of the selective delivery pumps fixedly installed, in order to reduce the pressure of the liquid flowing out from one of the discharge ports, at the position biased to the one outlet side from the midpoint of the working passage in the casing, It is characterized in that a pressure adjusting hole for connecting the inside of the casing and the liquid introduction path is provided.

(Operation) The operation will be described with reference to FIG.

When the impeller 10 rotates in the direction of arrow A, the liquid is discharged from the discharge port 34a.
Liquid is discharged from the discharge port and rotates in the direction of arrow B, the liquid is discharged from the discharge port.
It is discharged from 34b. The pressure of the liquid flowing through the working passage 18 is once reduced by the pressure adjusting hole 24 and then raised again. Therefore, the longer the distance between the pressure adjusting hole 24 and the discharge ports 34a, 34b, the discharge pressure of the liquid from the discharge ports 34a, 34b. Will be higher.

Therefore, since the distance between the pressure adjusting hole 24 and the discharge port 34a is longer than the distance between the pressure adjusting hole 24 and the discharge port 34b, the discharge port 3
The liquid discharge pressure at 4a is higher than the liquid discharge pressure at the discharge port 34b. Therefore, the pressure adjusting hole 24
Is biased toward the side where pressure reduction is desired from the center point of the working passage 18, the discharge pressure of one discharge port can be made lower than the other.

(Examples) Hereinafter, preferred examples of the present invention will be described in detail with reference to the accompanying drawings.

First, the configuration will be described.

In FIGS. 1 and 2, reference numeral 10 denotes an impeller having a large number of fins 12 provided on its peripheral surface, which is provided in a casing 14 so as to be rotatable around a shaft 16. A working passage 18 is formed between the outer circumference of the impeller 10 and the inner wall of the casing 14 so that the impeller 10 rotates to provide a pumping action. The working passage 18 preferably extends to about 80% of the outer circumference of the impeller 10.

The impeller 10 is connected to the output shaft 22 of the forward / reverse motor 20 as shown in FIG.

Reference numeral 24 is a pressure adjusting hole, which is formed in the inner wall of the casing 14 and communicates with a liquid introducing passage 30 described later. The pressure adjusting hole 24 is provided at a position deviated from the center of the working passage 18 by about 30 ° to the left with respect to the shaft 16 in the drawing.

26a is a valve chamber communicating with one end of the working passage 18. Further, 26b is also a valve chamber and communicates with the other end side of the working passage 18. Both valve chambers 26a and 26b are adjacent to each other and are partitioned by a partition wall 28. Further, a liquid introducing passage 30 is opened in the partition wall 28, and the liquid introducing passage 30 is opened by the suction port 32a.
And also communicates with the valve chamber 26b through the suction port 32b. The liquid introduction path 30 is connected to a liquid tank (not shown) by an appropriate connection pipe (not shown).

34a is a discharge port, which is opened on the wall surface of the valve chamber 26a facing the suction port 32a. In addition, 34b is also a discharge port, and the valve chamber 26b
Is opened on the wall surface facing the suction port 32b. The opening areas of the discharge ports 34a, 34b are the liquid introduction passage 30 and the suction port 32.
It is set smaller than the opening area of a and 32b.

Reference numeral 36a is a valve element that opens and closes the suction port 32a and the discharge port 34a of the valve chamber 26a. 36b is also a valve element, and opens and closes the suction port 32b and the discharge port 34b of the valve chamber 26b.

Both valve bodies 36a, 36b are fixed to both ends of a valve rod 38 having a cross-shaped cross section which is slidably supported in the left-right direction in the drawing by an appropriate member in the liquid introduction passage 30 and both suction ports 32a, 32b. There is. And
When the valve rod 38 moves, one valve body closes the suction port of the valve chamber and opens the discharge port, while the other valve body opens the suction port of the valve chamber and closes the discharge port. It is set to have a relationship.

The discharge port 34a is connected to an appropriate hose (not shown), and is connected to an injection nozzle (not shown) on the front window side of the automobile, and the discharge port 34b is connected to an injection nozzle (not shown) on the rear window side of the automobile.

Next, the operation will be described.

When the forward / reverse motor 20 is stopped and the impeller 10 is stationary, the valve body 36
The positions of a and 36b are not fixed, and it is in a free state. When the forward / reverse motor 20 is driven in this state to rotate the impeller 10 in the direction of arrow A, the liquid flows into the casing 14 through the liquid introduction passage 30. The liquid flows from the liquid inlet 30 to the valve rod 38.
Around the outer circumference, passes through the valve chamber 26b, flows through the working passage 18 in the direction of arrow A, and enters the valve chamber 26a. Then, the inside of the valve chamber 26b becomes a negative pressure and the inside of the valve chamber 26a becomes a positive pressure. While the impeller 10 continues to rotate, the pressure relationship between the valve chambers 26a and 26b continues to be in the above-described state, so this pressure difference causes the valve rod 38 to move to the left in the drawing and the valve element 36b to move to the valve. The discharge port 34b of the chamber 26b is closed and the suction port 32b is opened. At the same time, the valve element 36a is connected to the suction port 3 of the valve chamber 26a.
2a is closed and the discharge port 34a is opened (state shown in FIG. 1). Thereby, the liquid introduction passage 30, the suction port 32b of the valve chamber 26b,
A flow path that connects the valve chamber 26b, the working passage 18, the valve chamber 26a, and the discharge port 34a of the valve chamber 26a is formed, and the liquid is discharged from the discharge port 34a.

Conversely, when the impeller 10 rotates in the direction of arrow B, the valve chamber 26
a becomes negative pressure and the valve chamber 26b becomes positive pressure, and the valve rod 38 moves to the right in the drawing due to this pressure difference, so the valve element 36a closes the discharge port 34a of the valve chamber 26a, and the suction port 32a is closed. Open. Valve body at the same time
36b closes the suction port 32b of the valve chamber 26b and opens the discharge port 34b. This constitutes a flow path connecting the liquid introduction passage 30, the suction port 32a of the valve chamber 26a, the valve chamber 26a, the working passage 18, the valve chamber 26b, and the discharge port 34b of the valve chamber 26b, and the liquid is discharged from the discharge port 34b. It

Next, the operation of the pressure adjusting hole 24 will be described in detail with reference to FIGS.

FIG. 3 is a schematic view of the selective delivery pump of the embodiment shown in FIG.

When the discharge port 34a is closed (the discharge port 34b is
36b), the working passage when the impeller 10 rotates in the direction of arrow A and the liquid flows in the direction of arrow C.
The distribution of the fluid pressure at each point X, Y, Z in 18 is shown in FIG.

The rotation of the impeller 10 in the direction of the arrow A increases the liquid pressure while the liquid moves from the point X to the point Y. At point Y
Since the pressure adjusting hole 24 exists, the liquid pressure temporarily drops. Further, the rotation of the impeller 10 causes the liquid pressure to rise again, and the discharge port
At 34a (point Z), the liquid pressure shown by P1 acts.

The liquid pressure shown by the broken line shows the change in liquid pressure when the pressure adjusting hole 24 is not provided.

When the rotation of the impeller 10 is in the direction of the arrow B, the liquid flows in the direction of the arrow D, and the change of the fluid pressure at each point of X, Y and Z at that time is as shown in FIG. The liquid pressure increased by the rotation of the vehicle 10 in the direction of the arrow B once decreases at the point Y (pressure adjusting hole 24) and again increases, and the discharge port 34
The liquid pressure at b (point X) becomes the magnitude shown at P2. Also in FIG. 5, the liquid pressure shown by the broken line shows the liquid pressure when the pressure adjusting hole 24 is not provided.

Here, as shown in FIG. 4 and FIG.
The liquid pressure once lowered at the point Y where 24 is present rises again while reaching the discharge ports 34a and 34b, but the liquid pressure at the discharge port becomes higher as the distance between the pressure adjusting hole and the discharge port increases. . Therefore, as can be seen from FIG. 3 (or FIG. 1), the pressure adjusting hole 24 is located at the discharge port 34 rather than the midpoint of the working passage 18.
Since it is installed at a position offset to the b side, pressure adjustment hole 2
The distance between the pressure adjusting hole 24 and the discharge port 34a
Since it is longer than the distance from b, the fluid pressure at the discharge port 34a can be made higher than the fluid pressure at the discharge port 34b.

The actual change in liquid pressure is shown in FIG. This means that when the impeller 10 rotates in the direction of arrow A, the discharge port 34a is opened, that is, the discharge is performed at the point X (valve chamber 26b).
In the vicinity (), the impeller 10 is rotated to be in a negative pressure state, and since the point Y is still in a negative pressure state, the liquid is sucked from the pressure adjusting hole 24, the flow rate of the liquid is increased, and the impeller 10 is again rotated. The liquid pressure increases due to the rotation, and the liquid pressure indicated by P3 acts when the liquid pressure is discharged from the discharge port 34a.

If the pressure adjusting hole 24 is not provided, the discharge port 34
Since the liquid pressure shown in P4 is applied to a, the liquid pressure can be increased by the pressure adjusting hole 24.

When the impeller 10 is rotated in the reverse direction (the direction of arrow B), although not shown, if the liquid pressure at the point Y is positive, the liquid suction action does not occur. Even if the pressure is negative, the liquid pressure immediately before the point Y is higher than that when rotating in the direction of arrow A, so the amount of liquid sucked from the liquid pressure adjusting hole 24 is smaller than that when the rotating direction of the impeller 10 is arrow A. Furthermore, since the distance between the pressure adjusting hole 24 and the discharge port 34b is short, the liquid pressure at the discharge port 34b is equal to that of the impeller 10.
Becomes lower than when rotating in the direction of arrow A. Therefore, the discharge port 34
The discharge pressure of a can be set higher than the discharge pressure of the discharge port 34b.

Next, another embodiment will be described with reference to FIG.

Impeller 110, casing 112, working passage 114, discharge port 116
The configurations of a, 116b, the valve bodies 118a, 118b, and the valve rod 120 are the same as those of the embodiment shown in FIG. 1, but the tip of the liquid introduction passage 122 reaches the inside of the casing 112, and the tip thereof is a partition wall. 124
To define the valve chambers 126a and 126b. Therefore the partition
At the tip of the liquid introduction path 122 forming the suction port 128a,
128b is formed.

The pressure adjusting hole 130 is a liquid introducing passage on the valve chamber 126b side of the partition wall 124.
It is drilled to communicate with 122. Even in the case of this embodiment, the discharge pressure on the discharge port 116b side is lower than that on the discharge port 116a side. According to the method shown in FIG. 7, the difference in discharge pressure between the discharge ports 116a and 116b becomes large, and it is suitable when a large pressure difference is required.

Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and, for example, a check valve for preventing backflow may be provided at the discharge port. Of course, many modifications can be made without departing from the spirit of the.

(Advantages of the Invention) When the selective delivery pump according to the present invention is used, it is possible to reduce the discharge pressure of the liquid at one discharge port simply by providing the pressure adjusting hole without changing the rotation speed of the impeller. Become. Further, since the difference in discharge pressure can be easily changed by changing the amount of deviation of the pressure adjusting hole, a selective delivery pump having various kinds of pressure differences can be obtained without changing the basic structure of the pump. Can be provided. Further, since there is no external additional element such as pressure reducing means, it is possible to provide a selective delivery pump in which the discharge pressures of the front window and the rear window are different from each other without increasing the cost as compared with the conventional ones.

[Brief description of drawings]

FIG. 1 is a front view of a selective delivery pump according to an embodiment of the present invention, FIG. 2 is a side sectional view thereof, FIG. 3 is a schematic view for explaining its operation, and FIG. 4 shows an impeller in the direction of arrow A. FIG. 5 is a graph showing the change in liquid pressure when rotating, and in FIG.
The graph showing the change in liquid pressure when rotating in the 6th direction, 6th
FIG. 7 is a graph showing changes in liquid pressure when the impeller rotates in the direction of arrow A in an actual use state, and FIG. 7 is a front sectional view showing another embodiment. 10 …… impeller, 12 …… fin, 14 …… casing, 18 …… working passage, 20 …… forward / reverse motor, 22 …… output shaft, 24 …… pressure adjusting hole, 26a, 26b …… valve chamber, 28 ... Partition, 30 ... Liquid inlet, 32a, 32b ... Suction port, 34a, 34b ... Discharge port 36a, 36b ... Valve body, 38 ... Valve rod.

Claims (1)

[Claims] 1. A casing is provided with an impeller having a large number of grooves or fins on its peripheral wall, the impeller is connected to an output shaft of a forward / reverse motor, and a blade is provided between the casing inner wall and the impeller. A working passage for delivering a liquid by a pumping action due to the rotation of the vehicle is formed, and two valve chambers respectively communicating with the working passage are provided in the casing so as to be adjacent to each other. A liquid introduction path for introducing the liquid from the tank is provided, suction ports communicating the liquid introduction path with the valve chambers are opened in the partition walls, respectively, and a position on the inner wall of the valve chambers facing the suction ports is provided. A valve rod is provided at each of which the discharge port is opened, and the partition wall is movably inserted into the valve chamber so that both ends thereof project into each of the valve chambers. Open the inlet of the chamber When the discharge port is closed, in the selective delivery pump in which the valve body that closes the suction port of the other valve chamber and opens the discharge port is fixed, the pressure of the liquid flowing out from one discharge port is In order to lower the pressure, a selective delivery which is characterized in that a pressure adjusting hole that connects the inside of the casing and the liquid introduction path is provided at a position that is biased to one discharge port side from the midpoint of the working path in the casing. pump.