JPS62150100A - Pump chamber structure of washer pump - Google Patents

Abstract

PURPOSE:To aim at enhancing the efficiency of a washer pump, by specifying the relationship between the distance from the center axis of a motor shaft to that of an outlet pipe and the diameter of an impeller. CONSTITUTION:An outlet pipe 8 of a washer pump is integrally incorporated with a pump casing 2 similarly to an inlet 1. The ratio between the distance (I) from the center of a pump chamber 6 to the center of the outlet 8 and the diameter (r) of the impeller 5, that is, 1/r, is set to be greater than 1.0 but less than 1.1. Accordingly, fluid discharged by an impeller may smoothly flow into the outlet pipe, thereby it is possible to enhance the efficiency of the washer pump.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a centrifugal type washer pump for supplying washer fluid for washing to a vehicle window, and particularly relates to a centrifugal type washer pump that is operated with pressure characteristics. The present invention relates to a pump chamber structure suitable for obtaining good pump characteristics.

[Prior art]

Since the washer pump is mounted on a vehicle, it is desired that it be small and lightweight. Currently, many washer pumps use a centrifugal pump with an impeller outer diameter of approximately φ20. Furthermore, the washer pump is required to have a small flow rate and high pressure so that dirt can be more reliably removed using the washer liquid in the limited washer tank. Generally, in order to obtain high pressure with a centrifugal pump, there are ways to increase the outer diameter of the impeller or increase the rotation speed. However, in these methods, the flow rate also increases as the pressure increases. Also, due to the increased load on the impeller.

Secondary problems arise in terms of durability and vibration of the motor section, which is the pump drive section.

In addition, as related to the improvement of pump characteristics,
3-73604 is mentioned. This known technique aims to improve pump efficiency by reducing frictional loss within the pump by providing a collection chamber with a smoothly curved confinement wall in the pump chamber.

[Problem that the invention seeks to solve]

High-pressure pumps, such as washer pumps, have fewer discharge ports for small flows, so if a collection chamber is provided, the pump chamber, which has once expanded, will be discharged in an uneven manner, resulting in a loss of fluid. The above-mentioned known technology is difficult to apply to washer pumps because it results in a decrease in efficiency.

SUMMARY OF THE INVENTION An object of the present invention is to provide a window washer pump for a vehicle that has a small pump structure with high efficiency and low rotation speed, low flow rate, and high pressure.

[Means for solving problems]

First, the basic principle of the pump chamber structure of the present invention created to achieve the above object will be briefly described below.

The present invention provides an efficient pressure-type pump structure that smooths the flow of washer fluid within the pump by changing the position of the clearance outlet in the pump chamber without changing the dimensions of the impeller or increasing the rotation speed. That is.

In order to achieve the above object based on the above-mentioned principle, the pump chamber for the washer pump of the present invention allows two movements in the axial direction with respect to the shaft of the drive motor, so that the pump chamber for the washer pump of the present invention allows two movements in the axial direction with respect to the shaft of the drive motor. In a vehicle window washer pump of Sen1-Rifneygal type, which strikes a radially linear impeller fitted with an IJ and an outlet pipe arranged tangentially to the outer periphery of the pump chamber housing the impeller, the motor shaft and It is characterized in that 1.0<(l/r)<1.1, where Q is the axial distance from the outlet pipe and r is the radius of the impeller.

[Effect]

With the above configuration, as will be described later with reference to FIG. 3(a), the discharge flow smoothly flows through the outer pipes, a high discharge pressure is obtained at a low rotation speed, and efficiency is improved.

〔Example〕

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

FIG. 2 is a partial longitudinal cross-sectional view of a washer pump showing an embodiment of the present invention, and FIG. 1 is a cross-sectional view of the pump portion thereof.

The pump inlet 1-1 is integrally molded with the pump cover 2 using resin, and is configured to be attached to an opening (not shown) provided in the washer tank via a rubber seal. 3 is a motor shaft, and a water seal 4 is installed between the motor section on the right side of FIG. 2 and the pump section on the left side.

The impeller 5 is a centrifugal type having straight blades extending radially from the center, and is fitted to the shaft 3 in a floating manner. In this embodiment, the number of blades of the impeller 5 is six. The pump chamber 6 is formed by welding the pump case and the motor case 7.
Its shape is substantially concentric with the shaft 3 and has a substantially circular shape. The outlet pipe 8 is molded integrally with the pump case 2 like the inlet l. Here, the ratio Q/r of the distance α from the center of the pump chamber 6 to the center of the outlet 8 and the radius r of the impeller 5 is set to be 1.05. Further, the round gap G between the impeller 5 and the pump chamber 6 is 2 m.

As the motor shaft 3 rotates, the impeller 5
is driven. Due to the rotational force of the impeller 5, the washer liquid flows from the inlet 1, is given pressure, and flows to the outlet pipe 8.

The pump section and the motor section are sealed with a water seal 4.

Figure 4 is a characteristic chart comparing an example of applying the present invention with Q/r=1.05 (solid line) and an example of a conventional product with Q/r=0.97 (broken line). be.

It can be seen that when the pump chamber structure of this example is used, a high pressure can be obtained at a low rotation speed in a small flow rate region compared to the conventional product. Moreover, the current value is lower than that of conventional products in the entire flow range.

FIG. 5 is a graph in which the characteristics obtained when the above-mentioned dimensional ratio Q/r is changed are converted into values per revolution/number of revolutions (impeller circumferential speed). Here, the pressure coefficient ψ is φ=H/(U”/g), and the flow coefficient φ is φ=Q/(πD2U/4).

However, H: Pressure Q: Flow rate U: Circumferential speed of impeller D = Outer diameter of impeller g: Gravitational acceleration Figure 6 is based on the graph of Figure 5 described above as a graph of size ratio and pressure coefficient at cut-off. It has been replaced and the 1 dimension ratio is U/
It can be seen that the maximum value is shown near r=1.05. Since this pump is a high-pressure pump with a smaller flow rate than a general Centrifuge Nigal pump, the fluid discharged from the impeller is discharged approximately tangentially to the outer diameter of the impeller. Therefore, as shown in Figure 3(a), the outlet pipe is Q/r.
By being provided in the tangential direction at a position near = 1.05, the fluid discharged from the impeller can smoothly flow into the outlet pipe, and efficient pump characteristics with a small flow rate and high pressure can be obtained. Figure 3(b) shows Q/r=
When Q/r is 0.97 (C), it is when Q/r=1.12, and it can be seen that the loss of fluid flow becomes large.

By using the pump according to this embodiment, the efficiency is improved compared to conventional pumps, and high pressure can be obtained at low rotation speed, so the durability of the motor part, which is the Iψ movement side, is improved and noise and vibration are reduced. You can also get

〔Effect of the invention〕

As described above in detail, according to the washer pump chamber structure of the present invention, it is possible to construct an efficient washer pump of low rotation speed, small flow rate, and high pressure type.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of one embodiment of the present invention, and FIG. 2 is a partial vertical cross-sectional view of the same. Figure 3 is an explanatory diagram of the action of the present invention, Figure 4 is a pump characteristic diagram,
FIG. 5 is a correlation chart between flow rate coefficient and pressure coefficient, and FIG. 6 is a correlation chart between size ratio and pressure coefficient at closing. 1... Inlet, 2... Pump case, 3... Shaft, 4... Water seal, 5... Impeller, 6
...Pump room, 7...Motor case, 8...Outlet! □ Pipe. □, j71 Agent Patent attorney Katsuma Ogawa ・N fan 10 2nd (¥1 6 (, ↑, 'n i) 躬 30 (Q) 躬t-+-口5L l (1 (CC/lomc) certain 5 [ 211 Do Dimensions Hi '/r

Claims (1)

[Claims] 1. A radially linear impeller that is floatingly fitted to the shaft of the drive motor to allow sliding in the axial direction, and an outlet pipe that is arranged in a tangential direction to the outer periphery of the pump chamber that houses the impeller. In the centrifugal type vehicle window wash pump, where l is the axial distance between the motor shaft and the outlet pipe, and r is the radius of the impeller, 1.0<(l/r)<1. .1 Pump chamber structure of a washer pump.