JPH068296Y2 - Engine warm-up device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an engine heating device, and more particularly, to a heating device installed in an intake passage of an engine, regardless of the operating condition (rotational fluctuation) of the engine. The present invention relates to a warming device for an engine that can be stably burned.

[Conventional technology]

In recent years, a combustion device such as a burner is installed in the intake passage of the engine to increase the intake temperature at the time of starting the engine to improve engine startability, and a heat exchanger is provided on the downstream side of the combustion device. There is an attempt to connect the exchanger to the heating system of the vehicle to improve the capacity of the heating system immediately after the engine is started (Japanese Utility Model Application No. 58-165310).

However, if a burner is installed directly on the intake pipe of the engine, the flow rate and speed of the air flowing through the intake pipe will change due to engine rotation, so the burner will not be able to burn stably, and the burner will have unstable intake air. Since it may be blown out by the flow, not only the heater performance is not sufficiently obtained, but also the exhaust gas of the engine is adversely affected. The phenomenon of extinguishing the fire of the burner is particularly likely to occur in intake pulsation and backfire that occur at low engine speeds.

[Purpose of device]

The object of the present invention is to solve the problems of the conventional engine warm-up device, supply a constant amount of air to a combustion device such as a burner at any engine rotation speed, and further, intake pulsation and backfire in the intake pipe. Even if occurs, it is an object of the present invention to provide an excellent engine warm-up device capable of always causing the combustion device to stably burn by preventing the flame of the combustion device from being blown out.

[Constitution of device]

The engine warm-up device of the present invention which achieves the above object is provided with an intake bypass circuit bypassing the intake path in the middle of the intake path of the engine, and the intake bypass circuit communicates with the combustor and the heater unit of the vehicle. A heat exchanger is installed in this order, and a pressure regulating valve is further provided in an intake passage between a junction and a junction of the intake passage and the intake bypass, and the intake bypass downstream of the combustor has the It is characterized in that a check valve for preventing backflow of intake air from the intake passage is provided.

〔Example〕

 Embodiments of the present invention will be described below with reference to the accompanying drawings.

The drawing shows the structure of the engine warm-up device of the present invention, where 1 is an engine, 2 is an intake manifold, and 3 is an intake pipe.

In the present invention, an intake bypass 4 is installed in parallel with the intake pipe 3 in the middle of the intake pipe 3, and a combustor 5 provided with a burner 7 is provided on the upstream side of the intake bypass 3, and the combustor 5 is installed. The heat exchanger 8 is attached on the downstream side.

The combustor 5 is connected to a fuel injection pump 10 attached to the engine 1 by a fuel pipe 6, and a fuel tank
The fuel from 11 is burnt in the intake bypass 4,
The air outlet side of the heat exchanger 8 is connected to the heater unit 9 of the vehicle so that the warm air (indicated by an arrow H) that is heated by the heat exchange by the combustion gas of the burner 7 is heated by the heater unit 9.
It is configured to flow into.

Further, a check valve 15 such as a reed valve is installed on the downstream side of the heat exchanger 8 of the intake bypass 4 and on the upstream side of the confluence portion of the intake bypass 4 with the intake pipe 3. The intake air from the side 3 is prevented from entering from the downstream side of the intake bypass 4. It is desirable that the check valve 15 does not project its valve body into the intake pipe 3 when the check valve 15 is opened.

On the other hand, a portion of the intake pipe 3 that bypasses the intake bypass 4
A pressure regulating valve 12 is installed in the. This pressure regulating valve 12 is installed in order to always keep the differential pressure of the intake pipe 3 before and after the pressure regulating valve 12 constant. In this embodiment, the pressure regulating valve 12 has its rotating shaft 12
An arm 12b is attached to a, and this arm 12b is connected to a rod 13c protruding from the diaphragm 13a of the diaphragm type actuator 13. The spring chamber 13b of the actuator 13 is connected to a negative pressure sensor 14 installed in the intake pipe 3 on the downstream side of the pressure regulating valve 12 by a communication pipe 13d,
The pressure on the downstream side of 12 is introduced into this spring chamber 13b.

In the engine warm-up device of the present invention configured as described above, since the intake air flows through the intake bypass 4 by the action of the pressure regulating valve 12 immediately after the cold start of the engine 1, at this time, the combustor 5
The burner 7 is ignited to heat the intake air. The intake air thus heated warms the air for indoor heating by the heat exchanger 8 and is introduced into the engine 1 from the intake manifold 2 to enhance the warm-up property of the engine 1.

In this state, the pressure regulating valve 12 is driven by the actuator 13 according to the pressure detected by the negative pressure sensor 14. That is, the pressure regulating valve 12
Since the pressure in the spring chamber 13b becomes low when the pressure on the downstream side of the pressure chamber is low, the diaphragm 13a bulges toward the spring chamber 13b side, pulls the rod 13c into the actuator 13, and opens the pressure regulating valve 12 to increase intake. When the pressure in the spring chamber 13b rises when the pressure on the downstream side of the pressure regulating valve 12 is increased by flowing it toward the intake pipe 3 side, and conversely, the pressure on the downstream side of the pressure regulating valve 12 increases, the diaphragm 13a becomes a spring. Inflate to the opposite side of the chamber 13b and push the rod 13c out of the actuator 13,
The pressure regulating valve 12 is closed and the amount of intake air flowing through the intake pipe 3 is reduced to lower the pressure on the downstream side of the pressure regulating valve 12.

By such an operation of the pressure regulating valve 12, the pressure difference between the inlet portion and the outlet portion of the intake bypass 4 is always kept constant, so that the combustion air is not affected by the change in the intake air amount due to the change in the engine rotation. The air flow rate through the burner 7 of the vessel 5 is always kept constant, and the burner 7 burns stably without being blown out. Further, since the check valve 15 is provided in the vicinity of the junction with the intake pipe 3 on the outlet side of the intake bypass 4, the backfire of the engine 1 and the reverse flow of the intake air due to the intake pulsation exceed the check valve 15. There is no backflow into the intake bypass 4. Therefore,
The flame of the burner 7 is stably burned without being blown out, so that the warm-up of the engine 1 can be improved and the room can be quickly heated.

[Effect of device]

As described above, the engine warm-up device of the present invention is provided with an intake bypass path bypassing the intake path in the intake path of the engine, and the intake bypass path communicates with the combustor and the vehicle heater unit. A heat exchanger is installed in this order, and a pressure regulating valve is further provided in an intake passage between a junction and a junction of the intake passage and the intake bypass, and the intake bypass downstream of the combustor has the By providing a check valve that prevents the reverse flow of intake air from the intake passage, the pressure regulator maintains a constant pressure difference between the inlet portion and the outlet portion of the intake bypass 4, so the engine can be used in any condition. In any case, the amount of intake air flowing through the intake bypass 4 does not change, and a constant amount of air can be supplied to the combustion device such as a burner at all engine rotation speeds so that the combustion device can always perform stable combustion.

Further, by providing the check valve, it is possible to prevent backflow of intake air from the intake passage, and even if intake pulsation or backfire occurs in the intake passage, the flame of the combustor is blown out. Can be prevented.

As described above, the effect of being able to always improve the warm-up of the engine without being affected by the engine rotation speed and its variation at all and to heat the room immediately after the cold start. There is.

[Brief description of drawings]

FIG. 1 is a schematic view showing the structure of an engine warm-up device of the present invention. 1 ... Engine, 3 ... Intake pipe, 4 ... Intake bypass circuit, 5 ... Combustor, 7 ... Burner, 8 ... Heat exchanger, 12 ... Regulator, 13 ... Diaphragm, 14 ... Negative pressure sensor, 15 ... Check valve .

Claims (1)

[Scope of utility model registration request] 1. An intake bypass circuit that bypasses the intake path is provided in the intake path of the engine, and a heat exchanger that communicates with a combustor and a heater unit of the vehicle is installed in this intake bypass circuit in this order. Further, a pressure regulating valve is provided in the intake passage between the junction between the intake passage and the intake bypass and the confluence, and the backflow of intake air from the intake passage is prevented in the intake bypass downstream of the combustor. A warm-up device for an engine, which is provided with a check valve that operates.