JPH0291431A - Throttle valve body - Google Patents

Abstract

PURPOSE:To prevent a butterfly valve from pressurizedly contacting and icing up by forming a thick wall part of a resin body with a passage for heating fluid, and controlling dimentional contraction by partially exposing a metallic ring into the above-mentioned passage to heat the ring. CONSTITUTION:A shaft 2 and a butterfly valve 3 are arranged in a resin cylindrical throttle valve body 1, and an inner peripheral surface of the above-mentioned part of the body 1 is formed of the inner peripheral surface of a brass metallic ring 4. In addition, a thick wall part of the body 1 is provided with a passage 5 for heating fluid, and a peripheral surface of the metallic ring 4 is partially exposed into the passage 5. The quantity of heat held by the heating fluid is well transmitted to all over the metallic ring 4 from its exposed part, and can thereby prevent that the locking of the butterfly valve 3 is caused by icing.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a throttle valve body for an internal combustion engine;
In particular, it relates to a body made of resin.

Conventional Technology Throttle valve bodies for internal combustion engines have conventionally been manufactured by aluminum die-casting, but in the case of aluminum die-casting, post-processing is required because precision is not achieved without casting. Furthermore, since diegeast tends to form cracks and has poor airtightness, there are problems such as the need for sealing treatment.

Therefore, consideration has been given to using resin for the throttle valve body, with the aim of making it easier to process and reducing costs.

Problems that the invention aims to solve However, with a resin throttle valve body.

(1) Dimensional shrinkage of the body occurs due to use at high temperatures. A disc-shaped butterfly valve is disposed inside the cylindrical body, and the valve is rotated around the radial axis of the cylinder to control the flow, but due to the dimensional contraction, the periphery of the butterfly valve There is a risk that the butterfly valve will be in pressure contact with the inner surface of the body, and the butterfly valve will not be able to rotate.

(2) When the outside temperature is low, heating is performed from the outside of the body to prevent the butterfly valve from sticking to the inner surface of the body due to icing, but since the thermal conductivity of resin is lower than that of metal, the effect of preventing icing is small.

In view of the above points, it is an object of the present invention to provide a throttle valve body that is made of resin, and in which dimensional shrinkage due to heating, particularly in the portion where the butterfly valve is disposed, is suppressed. In addition to the above object, it is also an object of the present invention to provide a throttle valve body made of resin that can reliably prevent icing. The invention is characterized in that the cylindrical throttle valve body is made of resin, and the inner circumferential surface of the body in the part where the butterfly valve is installed is made of the inner circumferential surface of a metal ring inserted into the resin. The present invention is characterized in that a passage for heating fluid is formed in the thick part of the body, and at least a portion of the gold fi IJ ring is exposed in the passage.

Function: In the present invention, the inner surface of the body of the butterfly valve disposed portion is constituted by the inner circumferential surface of the metal ring. Due to the presence of the metal ring, it is possible to suppress dimensional shrinkage due to heating of this part and prevent the inner circumferential surface of the body from coming into pressure contact with the periphery of the butterfly valve.

In addition, the metal ring conducts heat better than resin, and at least a portion of the metal ring is exposed to the heating fluid passage formed in the thick part of the body, so the heat of the heating fluid is transferred to the butterfly valve installation area. This can be done to prevent icing.

Example Next, the present invention will be explained in detail.

In FIG. 1, 1 is a cylindrical throttle valve body made of resin, and is molded from glass fiber reinforced phenolic resin. A disc-shaped butterfly valve 3 that rotates around a cylindrical radial axis 2 is disposed within the body 1.
The inner circumferential surface of the body 1 in this disposed portion is constituted by the inner circumferential surface of a metal ring 4 made of brass. The metal ring 4 is integrated with the body 1 by insert molding.

When a gold 11J ring 4 with a thickness of 2 mm is used, the inner diameter of the body l (φ
The dimensional shrinkage of 55M) was 0.02 mm. on the other hand,
In the case without the metal ring, the same dimensional shrinkage was 0.1 mm. In this example, when butterfly valve 3 is closed,
The necessary clearance between the periphery of the butterfly valve 3 and the inner circumferential surface of the body 1 is 0.05 mm, and the dimensional shrinkage of the body 1 must be suppressed to 0.03n+n+ or less, but in this example, the dimensional stability is We were able to confirm the effect of

When the wall thickness of the lock and metal ring 4 is 0.8 mm, the dimensional shrinkage is 0.05 mm, and the wall thickness of the gold, II IJ ring 4 is set appropriately within the allowable range of dimensional shrinkage in actual use. do it.

Further, a heating fluid passage 5 was provided in the thick part of the body 1, and a part of the outer peripheral surface of the gold ring 4 was exposed to this passage.

From this exposed part, the heat of the heated fluid is well transmitted to the entire metal ring 4, and the butterfly valve 3 due to icing
can be prevented from locking.

FIG. 2 shows another embodiment, in which a convex portion 6 provided on the outer peripheral surface of the metal ring 4 is disposed in the passage 6. In this case, the main body of the metal ring 4 is embedded in the body 1 to ensure that the heated fluid is prevented from leaking into the body l through a small gap between the metal ring 4 and the resin that constitutes the body l. It is effective in doing so. Similarly, in terms of thermal conductivity, it is the first
There is no difference from what is shown in the figure.

By constructing the butterfly valve 3 and the metal ring 4 from the same material, it is more convenient to improve the clearance accuracy at high temperatures.

Effects of the Invention As described above, the present invention provides a throttle valve body made of resin, in which the inner circumferential surface of the body in the butterfly valve mounting portion is constituted by the inner circumferential surface of a metal ring. The presence of this metal ring can suppress dimensional shrinkage due to heating of the resin and ensure smooth operation of the butterfly valve.

In addition, at least a portion of the metal ring is exposed to the heated fluid passage formed in the thick part of the body to improve heat conduction to the entire metal ring, so it is possible to avoid locking of the butterfly valve due to icing.

[Brief explanation of the drawing]

FIGS. 1 and 2 are cross-sectional views showing embodiments of the present invention. l is the throttle valve body, 2 is the shaft, 3 is the butterfly valve, 4 is the metal ring, 5 is the passage, and 6 is the convex part.

Claims (1)

[Claims] 1. A throttle valve that includes a disc-shaped butterfly valve inside a cylindrical body and controls the flow rate by rotating the valve around an axis in the radial direction of the cylinder, in which the cylindrical body is made of resin. The throttle valve body consists of the inner circumferential surface of the body where the butterfly valve is installed, and the inner circumferential surface of the metal ring inserted into the resin. 2. The throttle valve body according to claim 1, wherein a passage for heating fluid is formed in a thick portion of the body, and at least a portion of the metal ring is exposed to the passage. 3. The throttle valve body according to claim 1, wherein a passage for heating fluid is formed in a thick portion of the body, and a convex portion provided on the outer peripheral surface of the metal ring is exposed to the passage.