JPH0443655Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electromagnetic flow control valve that is capable of controlling a flow rate unaffected by fluid pressure by controlling the current of an electromagnetic coil, and has an excellent valve closing function.

An example of a conventional electromagnetic flow control valve of this type is the one shown in US Pat. No. 4,362,027.
(See Figure 2) That is, in Figure 2, the electromagnetic coil 2
Plunger 2 by adjusting the energizing current of 5.
4 is adjusted, the valve body 16 connected to the plunger 24 is actuated, and the valve opening degree at the valve seat 44 is adjusted. As is clear from FIG. 2, the pressure of the refrigerant applied to the plunger 24 is
In order to equalize the pressure at the other end of the valve body 10, a pressure equalizing hole 41 is provided in the valve body 10 so that the plunger chamber and the first passage 13 side communicate with each other. This balances the load due to the pressure of the refrigerant acting on the front and rear of the valve body 16.

Now, consider the case where refrigerant flows from the first passage 13 to the second passage 14 side in this control valve. 1st
The refrigerant flowing from the second passage 13 side is throttled by the valve seat 44 and flows to the second passage 14 side. However, at this time, high-pressure refrigerant flows into the plunger portion through the pressure equalization hole 41 and passes through the gap between the valve body 16 and the valve body 10 into the second refrigerant.
leakage from the passage 14 side. This leakage amount is calculated from the valve body 16.
Since it is determined by the gap between the refrigerant and the valve body 10, it is impossible to set the same amount for each product, and therefore it is impossible to precisely control the flow rate of the refrigerant. Further, even when the valve body closes the valve seat 44, this amount of leakage still exists, so that the closing function of the valve is significantly impaired. This also applies when the refrigerant flows from the second passage side to the first passage side.

Furthermore, as described above, since refrigerant leaks and flows in the gap between the valve body 16 and the valve body 10, a refrigerant pressure gradient tends to occur between the pressure of the plunger portion and the first passage 13 side, and therefore, the expected Valve body 16
It is not possible to balance the pressure of the refrigerant on the

That is, when the refrigerant flows from the first passage 13 side to the second passage 14 side, the pressure in the plunger section becomes lower than that on the first passage 13 side, and the pressure in the plunger part becomes lower than that on the first passage 13 side. When the refrigerant flows to the valve body 16, a pressure gradient of 100,000 tons is generated, and the refrigerant pressure applied to the valve body 16 in accordance with the pressure gradient causes a load in the valve closing direction in the former case, and in the valve opening direction in the latter case.

This load depends on the pressure gradient between the plunger part and the first passage 13 side, that is, the amount of refrigerant leaking between the valve body 10 and the valve body 16, and is a uniform value for each product. This is extremely inconvenient when precise refrigerant flow rate adjustment is required.

In addition, especially when the refrigerant flows from the second passage 14 side to the first passage 13 side, the pressure of the refrigerant flowing out from the valve seat 44 is below the valve 43 and near the pressure outlet hole 45 of the pressure equalization hole 41. Since the pressure distribution is different between the two, the above-mentioned drawbacks are further increased.

Therefore, when such a control valve is used to control a uniform flow rate of refrigerant in the forward and reverse directions, it becomes a fatal flaw because the power input to the electromagnetic coil 25 and the valve opening have different characteristics in the forward and reverse directions. .

The present proposal was proposed in view of the above points, and according to the present proposal, a first passage through which the refrigerant passes, a second passage through which the refrigerant also passes, and a valve body having a valve seat provided between the two passages; An example of an electromagnetic coil provided in the valve body, which slides inside the valve body by this electromagnetic coil, has the same cross-sectional area as the diameter of the valve seat, has a plunger chamber in the upper part, and is further away from the plunger chamber. A plunger having a small diameter portion, which is integrally coupled with the plunger, moves within the valve body by the sliding movement of the plunger to open and close the valve seat within the second passage, and is always biased toward the valve seat by a spring. and a valve body supported by a valve member having a flange so as to face the small diameter portion, and an equalizer penetrating the valve member and the plunger, with one end opening into the second passage and the other end opening into the plunger chamber. a bush inserted between the pressure hole, the small diameter part and the flange of the valve member so as to surround the small diameter part of the plunger and the valve member; and a bush provided between the bush, the flange and the plunger, with the plunger side facing The main feature is that the central valve body side has a packing whose flange side is inclined toward the central plunger side, and is a reversible solenoid that allows the valve opening degree to be precisely adjusted only by input power to the solenoid coil. A flow control valve is provided.

The present invention will be explained below with reference to an embodiment shown in FIG. 51 is a valve body that connects the first passage 52 and this first passage.
It has a second passage 53 communicating orthogonally to the passage. 54 is a valve seat provided in the second passage.
The valve body 51 has a cylindrical portion 55 formed in its upper portion, and a plunger 56 having the same cross-sectional area as the valve seat is slidably held within the cylindrical portion. 5
Reference numeral 7 is an electromagnetic coil that surrounds the cylindrical portion 55 and is provided on the upper part of the valve body 51. Reference numeral 58 denotes a sealing fitting which is provided above the plunger 56 and forms a plunger chamber 59 between it and the plunger. 60
shows a spring. A valve member 61 is disposed within the valve body 51.
is positioned and inserted below the plunger 56 as shown in FIG. This valve member 61 is provided with a flange 62 near the plunger, and between this flange 62 and the plunger 66 is a small diameter portion 63 of the plunger,
A bushing 64 is fitted to surround the valve member 61.

However, the stepped portion 65 of the plunger 56 with the small diameter portion 63 is inclined so that the center is directed downward, and the upper end surface 66 of the bush 64 opposite to this stepped portion has a similar inclined surface. The lower end surface 67 of the bush 64 is an inclined surface with the center facing upward, and the collar 62 of the valve member 61 faces this lower end surface.
The upper surface 68 of has a similar sloped surface.

and the stepped portion 65 and the bush 6 of the plunger 56.
Packings 69,
70 has been inserted.

The packings 69 and 70 are circular thin plate packings having a diameter slightly larger than that of the cylindrical portion 55, and are preferably flexible members with low frictional resistance.

A valve body 71 is provided at the lower end of the valve member 61 and is opposed to the valve seat 54 . An adjusting nut 72 is screwed onto the valve body 51, and a spring 73 having a smaller elasticity than the spring 60 is inserted between the nut and the valve body 71.

However, pressure equalizing holes 74 and 75 are provided in the center of the plunger 56 and the valve member 61, respectively, passing through the plunger 56 and the valve member 61 vertically.

Next, the operation of the proposed control valve will be described. In the illustrated state, the coil 57 is energized, the plunger 56 rises against the elasticity of the spring 60, and the valve body 71 moves toward the valve seat 54.
The figure shows a state in which the person is seated on the vehicle and the first passage 52 and the second common passage 53 are blocked. In such a state, the refrigerant does not flow to the evaporator, so the temperature of the evaporator gradually increases.

When the temperature rise of the evaporator reaches a predetermined value, the coil 57 is deenergized by a signal from a control section (not shown). When the coil 57 is deenergized, the plunger 56 descends as shown in the figure due to the elasticity of the spring 60 and the valve member 61
The valve body 71 is spaced apart from the valve seat 54 via the valve body 71 to allow a predetermined amount of refrigerant to flow from the first passage 52 to the second passage 53 to control the evaporator at a predetermined temperature.

However, according to the present proposal, the valve seat 54 and the plunger 56
Since the cross-sectional area of the first passage 52 is equal, the refrigerant pressure in the first passage 52 acts equally on the collar 62 of the valve member and the valve body 71, and no refrigerant pressure gradient occurs between them.
Also, the refrigerant pressure in the second passage 53 is
5 and 74 on the upper surface of the plunger 56, and the other acts on the lower surface of the valve body 71, but no pressure gradient is created between them.

Furthermore, according to the present invention, the center of the packing 69 is inclined downward, and the center of the packing 70 is inclined upward, so that the refrigerant that passes from the plunger chamber 59 through the sliding portion of the cylindrical portion 55 and the plunger 56 flows through the packing 69.
This prevents leakage into the first passage 52.

Since the packings 69 and 70 have a slightly larger diameter than the cylindrical portion 55 and are made of flexible members,
The outer periphery is inscribed in the cylindrical portion 55 in a bowl shape. Therefore, when a pressure difference occurs here, the outer periphery of the packing is pressed against the cylindrical portion 55, and a sealing effect is obtained. Frictional resistance of packing and cylindrical part 55
The smaller the machined surface roughness is selected, the smaller the sliding resistance can prevent refrigerant leakage.

Furthermore, since the refrigerant in the first passage 52 is similarly blocked by the packing 70, it will not leak into the plunger chamber 59.

Therefore, assuming that the first passage 52 side is the high pressure side and the second passage 53 side is the low pressure side, the influence of the refrigerant pressure acting on the valve body will be canceled out on both the high pressure side and the low pressure side. By packing as described above, sealing performance can be exhibited in both forward and reverse directions, so that precise refrigerant control can be performed in accordance with the amount of power input to the electromagnetic coil.

That is, the same effect can be expected regardless of whether the first or second passage is on the high pressure side, and this is particularly effective when the refrigerant is used in both forward and reverse directions, such as in a heat pump.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of the control valve of the present invention, and FIG. 2 is a similar sectional view of a conventional control valve. 51... Valve body, 52... First passage, 53...
... Second passage, 54 ... Valve seat, 56 ... Plunger, 57 ... Electromagnetic coil, 59 ... Plunger chamber, 61 ... Valve member, 67, 70 ... Packing, 71 ... Valve body, 74, 75...Pressure equalization hole.

Claims (1)

[Scope of utility model registration request] A valve body 5 having a first passage 52 and a second passage 53 through which a refrigerant passes, and a valve seat 54 provided between the passages.
1 and an electromagnetic coil 57 provided in this valve body 5.
The plunger is a plunger that slides inside the valve body 51 by the electromagnetic coil 57, has the same cross-sectional area as the diameter of the valve seat 54, has a plunger chamber 59 in the upper part, and has a diameter on the side farther from the plunger chamber 59. The plunger 56 has a small diameter portion 63 and a flange 62 on the side opposite to the plunger small diameter portion 63 and is coupled to the plunger 56 by a bush.
The valve member 6 moves within the valve body 51 by sliding of the valve member 6.
1, a valve body 71 provided on the valve member 61 and always biased toward the valve seat 54 by a spring 73 to open and close the valve seat 54 within the second passage 53; and the valve member 61 and the plunger 56. pressure equalizing holes 74 and 75 that penetrate through and open to the second passage 53 at one end and open to the plunger chamber 59 at the other end; and the plunger small diameter portion 63.
and a bushing 64 inserted between the valve member flange 62 and the valve member 62 so as to surround the small diameter portion 63 and the valve member 61.
A gasket 6 is provided between the bush 64 and the plunger 56 and whose center is inclined toward the valve body 71.
9, and a packing 70 which is provided between the bush 64 and the valve member collar 62 and whose center is inclined toward the plunger 56.