JPH0640919Y2 - Vaporizer heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a heating device for preventing icing in the vicinity of a slow air bleed (low speed air bleed) of a carburetor.

[Conventional technology]

Conventionally, it promotes atomization of fuel at idling and starting,
In addition, in order to prevent icing during cold weather, various devices have been devised in which the fuel in the slow fuel passage is heated by engine cooling hot water or an electric heater.

For example, in Japanese Patent Publication No. 56-53094, a semiconductor positive temperature characteristic thermal resistance element (Posi
A heater for burying and heating a tive temperature coefficient (hereinafter referred to as PTC heater) is described. In Japanese Utility Model Laid-Open No. 60-73859, an insulator is sandwiched between a carburetor and an intake manifold,
An apparatus has been proposed in which an electric heater is embedded in the insulator to heat the vaporizer.

[Problems to be solved by the device]

When the engine is operated under conditions of low temperature and high humidity, the condensed ice adheres to the slow air bleed due to the heat of vaporization to cause a so-called icing phenomenon, which may reduce or block the air bleed passage. This phenomenon causes the air-fuel ratio to become rich and causes rough idle and engine stall.

As a countermeasure against the above-mentioned icing, it is conceivable to heat the carburetor in the vicinity of the slow air bleed with a PTC heater, engine cooling hot water or the like as described in the above-mentioned conventional technique. However, in this method, in the case of slow air bleed, most of the mounting parts are made of aluminum with good heat conduction, so when heated, percolation due to the temperature rise of the carburetor body and the air-fuel ratio of the slow system The adverse effect of fluctuations occurs.

In view of the above problems, it is an object of the present invention to provide an icing prevention measure that can prevent the temperature of the carburetor body from rising and can warm only the vicinity of the slow air bleed.

[Means for Solving the Problems]

In order to solve the above problems, in the present invention, the slow air bleed of the carburetor is press-fitted into a conduit having high thermal conductivity,
A carburetor icing, characterized in that the conduit is attached to the carburetor body through a sleeve having a lower thermal conductivity than the conduit and the carburetor body, and a heat plate is arranged so as to contact the conduit. A heating device for prevention is provided.

[Action]

The heat given by the heating means is transmitted through the conduit having high thermal conductivity to warm the slow air bleed, and the temperature in the vicinity thereof rises. Also, the heat transferred to the conduit is blocked by the heat insulating member surrounding the conduit and the amount of heat transferred to the carburetor main body around the sleeve is small, so the temperature rise of the carburetor main body is very small and the vicinity of the slow air bleed. Only the part is concentrated and heated to prevent icing.

〔Example〕

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

FIG. 1 is a longitudinal sectional view of a heating device near the slow air bleed of the vaporizer according to the first embodiment, and FIG. 2 is a partial transverse sectional view of the device.

The structure and operation will be described below with reference to FIG.
1 is a float chamber, 2 is a main jet, 3 is a slow jet, 4 is a first slow air bleed, 5 is an economizer jet, 6 is a second slow air bleed, 7 is a slow port, 8 is an idle port, 9 is a throttle valve, 27
Is a body, and 29 is an intake passage. The fuel stored in the float chamber 1 passes through the main jet 2 and is metered by the slow jet 3. Then, the air that flows in from the first slow air bleed 4 and the second slow air bleed 6 that are respectively provided on the upstream and downstream sides of the economizer jet 5 is mixed, and fuel is introduced from the slow port 7 and the idle port 8 into the intake passage 29. Erupted.

The slow air bleeds 4 and 6 are press-fitted into the conduits 10 and 11 having high thermal conductivity, respectively. The conduit is press-fitted into the air horn portion 14 via sleeves 12 and 13 having lower thermal conductivity than the conduits 10 and 11 and the air horn portion 14 of the carburetor main body 30 (the portion forming the air intake port in the upper portion of the carburetor main body). Have been assembled. As shown in FIG. 1, the heads of the conduits 10 and 11 project from the surface of the air horn portion 14, and the heat plate 15 is in contact therewith. Heat plate 15 to this
One end of the PTC heater 16 is in contact, and a material such as copper is used to efficiently transfer the heat of the PTC heater 16 to the conduits 10 and 11. An electrode 17 is in contact with the other end of the PTC heater 16 via an insulator 18 so as to receive the load of a spring 19. 20
Is a cover, and the PTC heater 16, the heat plate 15 and the like are fixed to the air horn portion 14 using the packing 21 as a sealing material. The ignition switch is turned on when the PTC heater 16 is energized (22).
And the battery voltage or equivalent is applied.

The air bleed passages 23 and 24 shown in FIG. 2 are formed in the air horn portion 14 and open to the through cylinder 26. Second
As shown in the figure, the air bleed passages 23, 24 are
Through the through cylinder 26.

As described above, according to the present embodiment, in order to facilitate heating of the slow air bleed, the slow air bleed is efficiently incorporated by incorporating it into a conduit made of a material having good heat conduction and heating only the conduit. It has become possible to warm up and take icing prevention measures. In particular, by providing slow air bleeding related members in the air horn, it becomes relatively easy to supply heat from the outside only to the necessary parts, and it is possible to achieve a quick rise in temperature with a small amount of heat. There is a merit that can be done.

From the above, it is possible to take appropriate measures to prevent icing of the slow air bleed, and since excess heat is not given to the carburetor body, even against percolation at high temperature and fluctuation of air-fuel ratio of slow system However, it is possible to avoid the disadvantage that there is a heating device for the vaporizer as in the conventional case.

Next, FIGS. 3 and 4 show a second embodiment applied to a vaporizer having a hot water heating wax type full auto choke. Less than,
Explaining with reference to the drawings, the air horn portion 14 includes a heater 31 having a built-in wax and a heat insulator 32.
Is attached through. Reference numeral 33 is a member for attaching the actuator 31 to the air horn portion 14. Also,
34 and 35 are inlet pipes and outlet pipes of engine cooling hot water. Wax stroke is rod 36
Although not shown, it is used for controlling the opening of the choke valve and throttle valve.

In the carburetor having the above structure, the heat transfer plate 37 is provided so as to be sandwiched between the actuator 31 and the heat insulator 32, and the heat transfer plate 37 is connected to the heat plate 40 via the conductor 39 wrapped with the heat insulating coating 38. The heat plate 40 is brought into contact with the conduits 10 and 11 by the biasing force of the spring 19. Hereinafter, since the engagement states of the conduits 10, 11 with the slow air bleeds 4, 6 and the sleeves 12, 13 (see FIG. 1) are the same as those in the first embodiment, the description thereof will be omitted.

It should be noted that the heat transfer plate 37, the conductor 39, and the heat plate 40 may be made of any material having good heat conduction, but generally a copper-based metal is preferable. The configuration of the vaporizer main body other than the above is
Since it is similar to the first embodiment shown in the figure, illustration and description thereof will be omitted.

With the above configuration, the heat generated by the hot water of the actuator can be efficiently transferred to the slow air bleed, which is a part required for the icing prevention measure. This effectively prevents icing, and since there is no extra heating of the carburetor body, there is no adverse effect on performance due to the carburetor becoming hot. Further, in this case, there is no need to newly provide a heat source, which is advantageous in terms of cost.

In each of the above examples, the case where the slow air bleed is attached to the air horn portion of the carburetor body has been described, but the attachment position of the slow air bleed is not limited to the air horn portion, and In this case, for example, it may be mounted in the body without any problem, and it is sufficient to have the above-described structure in which a conduit having high thermal conductivity and a sleeve having low thermal conductivity are combined.

〔The invention's effect〕

By using the heating device of the carburetor according to the present invention, the temperature rise of the carburetor main body is made small, and only the vicinity of the slow air bleed is partially concentrated and warmed, and accurate icing prevention is performed, and the carburetor is also calibrated. There is no adverse effect on the high temperature performance such as percolation at high temperature and fluctuation of the air-fuel ratio of the slow system.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a heating device using a PTC heater near the slow air bleed of the vaporizer according to the first embodiment, and FIG. 2 is a partial cross-sectional view of the device shown in FIG. FIG. 4 is a partial vertical cross-sectional view of a heating device using hot engine cooling water for a carburetor according to the embodiment shown in FIG. 2, and FIG. 4 is a plan view of the device shown in FIG. 4,6 …… Slow air bleed, 10, 11 …… Conduit, 12, 13 …… Sleeve, 15, 40 …… Heat plate, 30 …… Vaporizer body.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Susumu Nogami 1 Toyota-cho, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Tokio Yamauchi 1-1-1, Kyowa-cho, Obu City, Aichi Prefecture Within Kogyo Co., Ltd. (56) References Open 59-172259 (JP, U) Open 59-172258 (JP, U) Open 60-183261 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A carburetor slow air bleed is press-fitted into a conduit having high thermal conductivity, the conduit is attached to the carburetor main body through a member having a heat insulating property, and means for heating the conduit is provided. A heating device for preventing icing of a vaporizer characterized by the above.