JPH1024721A - Heating system for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating system for a vehicle excellent in controllability and the mounting property on the vehicle and capable of reducing the cost with a simple structure. SOLUTION: A pressure valve 31 controlling the discharge pressure of a hydraulic pump 2 and a heat exchanger 41 exchanging heat with a hydraulic fluid are assembled into a power steering device provided with a hydraulic pump 2 driven by a vehicle engine 1. When the pressure valve 31 is driven by a control device 32 so that the discharge pressure of the hydraulic pump 2 becomes the target pressure corresponding to the required heat quantity, the heat quantity corresponding to the target pressure is applied to the hydraulic fluid, and the temperature rises. The high-temperature hydraulic fluid is heat- exchanged with the engine cooling water by the heat exchanger 41, and the heat quantity required for heating a car room can be obtained with good controllability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device for a vehicle, and more particularly to a heating device for a vehicle that is effectively used as an auxiliary heating device for a vehicle equipped with a power steering system having a hydraulic pump.

[0002]

2. Description of the Related Art As a heating device for a vehicle driven by an engine, a device for guiding high-temperature engine cooling water to a heater core and exchanging heat with vehicle interior air is generally used. However, in recent years, the amount of heat that can be extracted from the engine cooling water has been reduced with the improvement in engine efficiency and the reduction in idling. For this reason, there is a concern that the heating performance may be deteriorated, especially in cold regions, and as a countermeasure against this, a combustion type heater or an electric type heater is used in combination to compensate for the lack of heat.
It has been proposed to improve the heating performance (Japanese Unexamined Patent Publication No.
-89334).

[0003]

However, the combustion type heater has a complicated structure, is likely to be large, and has a high manufacturing cost. Further, since it is necessary to maintain a constant combustion state, the controllability when the required heat amount is small, for example, is not very good. Although the electric heater has good controllability, it uses electricity as a heat source and consumes a large amount of power. Therefore, it has disadvantages such as a need to increase the size of a vehicle-mounted battery and a high operating cost.

An object of the present invention is to provide a simple structure,
An object of the present invention is to provide a heating device for a vehicle which is excellent in controllability, is excellent in mountability in a vehicle, and can reduce cost.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a vehicle heating device having the structure of claim 1 has the following features.
An internal combustion engine that provides a driving force to the vehicle, a fluid pump driven by the internal combustion engine, a pressure adjusting unit that controls a discharge pressure of the fluid pump, and a heat exchange unit that performs heat exchange with the working fluid ing. The pressure adjusting means increases the calorie of the working fluid by increasing the discharge pressure of the fluid pump, and the heat exchange means receives the increased calorie by heat exchange and heats the inside of the vehicle. To supply heat for use.

In the above configuration, when the discharge pressure of the fluid pump is controlled to a high pressure using the pressure adjusting means, the power supplied from the internal combustion engine to the fluid pump increases, and the amount of heat corresponding to the control pressure is supplied to the working fluid. The temperature rises. Thus, the working fluid having a high temperature is guided to the heat exchanging means, and the heat exchange is performed, so that the amount of heat required for heating the cabin can be obtained with good controllability.

[0007] The vehicle heating apparatus having the above-described structure has a relatively simple structure in which a fluid pressure pump and a heat exchange means are provided in a fluid pump driven by an internal combustion engine of the vehicle. It can be made more compact than the heater,
Excellent mountability on vehicles. Further, the manufacturing cost and the operating cost are low, and the economy is excellent.

More specifically, the pressure adjusting means sets and changes the target value of the discharge pressure of the fluid pump in accordance with a required amount of heat.

In the above configuration, when the amount of heat required for heating is input to the pressure adjusting means, the discharge pressure of the fluid pump is set to a target value calculated from the required amount of heat, and the amount of heat corresponding to the set pressure is set to the above-mentioned value. Provided to the working fluid.
Therefore, by resetting the target value of the discharge pressure in accordance with the change in the required heat amount, the heat amount required for heating can be generated with high responsiveness and high accuracy.

Alternatively, the pressure adjusting means may control the discharge pressure of the fluid pump to a predetermined pressure while the amount of heat is required. it can.

In the above configuration, when a heat quantity for heating is required, the discharge pressure of the fluid pump is controlled to a predetermined set pressure, and the heat quantity corresponding to the predetermined pressure is given to the working fluid. If this calorie is less than the required calorie,
The heat quantity request is made again, and the heat quantity corresponding to the predetermined pressure is generated again. This operation is repeated so that the total amount of heat obtained matches the required heat. Also in this case, a necessary amount of heat can be reliably obtained, and a desired effect can be obtained with a simple configuration.

According to a fourth aspect of the present invention, the fluid pump comprises:
Hydraulic pump for power steering device. In this way, if you use devices that are conventionally mounted on vehicles,
The configuration is simpler, and further downsizing and cost reduction are possible.

[0013] Specifically, the heat exchanging means may be,
A heat exchanger that transfers the heat amount of the working fluid discharged from the fluid pump to the cooling water of the internal combustion engine, and receives the heat amount for heating from the cooling water of the internal combustion engine into the vehicle. It consists of a heater core to be introduced.

Specifically, the pressure adjusting means comprises a pressure control valve and a control device for driving the pressure control valve.

According to a seventh aspect of the present invention, the control device includes an arithmetic unit for continuously calculating a target value of the discharge pressure of the fluid pump according to a required amount of heat. And an arithmetic unit for continuously determining whether or not a pressure request is required in accordance with the condition. The former arithmetic device enables the discharge pressure control as described in claim 2, and the latter arithmetic device enables the discharge pressure control as described in claim 3.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example in which a heating device of the present invention is applied to an auxiliary heating device of an air conditioner for a vehicle will be described. FIG. 1 is an overall configuration diagram of an auxiliary heating device, 1 is an automobile engine as an internal combustion engine of a vehicle, 2 is a hydraulic pump 2 for a power steering device as a fluid pump, and the hydraulic pump 2 is connected via a V-belt. It is driven by the engine 1.

The hydraulic pump 2 has pressure adjusting means 3 for controlling the discharge pressure P thereof. The pressure adjusting means 3 comprises a pressure control valve 31 and a control device 32. The pressure control valve 31 receives a drive signal from the control device 32 and controls the hydraulic oil discharge pressure P to a predetermined value. As a result, the hydraulic oil discharged from the hydraulic pump 2 is given a heat quantity proportional to the product of the discharge capacity, the number of revolutions N, and the discharge pressure P of the hydraulic pump 2 to increase the temperature.

The control device 32 includes an arithmetic unit 33 and a drive unit 34. The calculation device 33 includes a temperature detection device 35 that detects the temperature of the discharge oil, a rotation speed detection device 36 that detects the rotation speed of the hydraulic pump 2, and a necessary heat amount calculation device 37.
And outputs a target value Pc of the discharge pressure P of the hydraulic pump 2 calculated to the drive unit 34 based on these signals in accordance with a predetermined algorithm. The driving device 34 controls the current supplied to the pressure control valve 31 according to the target value Pc.

The hydraulic oil discharged from the hydraulic pump 2 and given heat by the pressure adjusting means 3 in accordance with the discharge pressure is introduced into a heat exchanger 41 arranged in a cooling water flow path of the engine 1. And exchange heat with the engine cooling water. The engine cooling water that has received the calorie of the working oil by heat exchange is then introduced into a heater core 42 for heating incorporated in the main body of the automotive air conditioner, and exchanges heat with air guided to the heater core 42 by a blower (not shown). I do. The air heated by this supplies the heat quantity for heating to the vehicle interior. The heat exchanger 41 and the heater core 42 constitute the heat exchange means 4.

The working oil that has exchanged heat with the engine cooling water in the heat exchanger 41 is guided to the gear box 5 of the power steering device. The gear box 5 assists the steering force by using the hydraulic pressure generated by the hydraulic pump 2. Power steering gearbox 5
Hydraulic fluid accumulates in the reservoir 6 and is guided to the hydraulic pump 2 again.

Next, the operation of the auxiliary heating device of the automotive air conditioner having the above structure will be described. In a hydraulic power steering apparatus of an automobile, a hydraulic pump 2 is driven by a V-belt by an engine 1, and a predetermined amount of hydraulic oil is constantly supplied to a gear box 5. When the driver turns the steering wheel, a hydraulic valve (not shown) incorporated in the gear box 5 switches the flow path and the throttle opening, so that the pressure for generating an assist force according to the degree of steering is reduced. It occurs as a differential pressure of around 5, which appears as the discharge pressure P of the hydraulic pump 2.

The power required to generate the discharge pressure P is supplied from the engine 1 to the hydraulic pump 2 and transmitted to the hydraulic oil. Actually, the power for steering is a small amount of the power supplied from the engine 1 to the hydraulic pump 2, and most of the power is used for increasing the temperature of the hydraulic oil. However, in normal driving, the time required for steering is short,
The rise in the discharge oil temperature T of the hydraulic pump 2 is small.

The auxiliary heating device according to the present invention increases the power applied from the engine 1 to the hydraulic pump 2 by continuously maintaining the discharge pressure P of the hydraulic pump 2 at a high pressure by using the pressure control valve 31. The oil temperature T is raised, and the amount of heat generated thereby is transferred to the engine cooling water using the heat exchanger 41. The high-temperature engine cooling water is guided to the heater core 42 of the vehicle air conditioner body, so that a sufficient amount of heat for heating the vehicle interior can be secured.

When the auxiliary heating device operates, the discharge pressure P
Even if the steering operation is performed in a state where the pressure is increased, the amount of hydraulic oil circulating in the hydraulic device does not change, and the differential pressure across the gear box 5 is generated as usual. When the differential pressure is lower than the discharge pressure P during the operation of the auxiliary heating device, the discharge pressure is maintained at the same pressure by the action of the pressure control valve 3. On the other hand, when the differential pressure across the gear box 5 is higher than the discharge pressure P at which the auxiliary heating device is operating, the discharge pressure P increases regardless of the driving state of the pressure control valve 3, and It is operated with a differential pressure of around 5.

As described above, in any case, a necessary differential pressure is generated before and after the gear box 5 in accordance with the steering operation, so that the function of the power steering apparatus does not cause a problem.

FIG. 2 shows an operation example of the auxiliary heating device. The figure shows the case where the air conditioner main unit starts heating operation in the idling operation state of the car, starts running after the inside of the vehicle has warmed up to some extent, and the engine speed goes up and down. The graph shows a temporal change of a required heat quantity Q required for the device, a rotation speed N of the hydraulic pump 2, and a target pressure Pc of the discharge pressure P. The required heat amount Q is calculated by the required heat amount calculation device 37 of the air conditioner main body, and the rotation speed N is detected by the rotation speed detection device 36 and input to the calculation device 33 of the control device 32 (FIG. 1). The calculation device 33 calculates the target pressure Pc based on these input signals.

FIG. 3 shows a calculation flowchart of the calculation device 33. First, after the start of step S0, in step S1, the required amount of heat Q and the number of revolutions N of the hydraulic pump 2 required by the air conditioner body for the auxiliary heating device are input from the required amount of heat calculating device 37 and the number of revolutions detecting device 36, respectively. In step S2, a target pressure Pc of the discharge pressure P of the hydraulic pump 2 is calculated from the required heat quantity Q and the number of revolutions N. Since the heat quantity Q generated by the hydraulic pump 2 is proportional to the product of the discharge capacity per revolution, the number of revolutions N, and the discharge pressure P, in step S2, the target pressure Pc is calculated using the coefficient k, and Pc = kQ / N .. (1), the required heat quantity Q required by the air conditioner main body is calculated.
To fit.

In step S3, the discharge oil temperature T is input from the temperature detecting device 35, and the flow advances to step S4. In step S4, the discharge oil temperature T is set to 90 to 10 in advance.
This is compared with the maximum discharge temperature Tmax set at about 0 ° C.
If the determination of (T ≦ Tmax) is YES, the process proceeds to step S6. When the determination of (T ≦ Tmax) is NO, that is, when the discharge oil temperature T becomes the maximum discharge temperature Tmax
If higher, the process branches to step S5,
5 The discharge oil temperature T and the preset maximum discharge temperature T
The target pressure Pc is reset according to the difference between max. The equation of step S5 is that the higher the discharge oil temperature T, the higher the target pressure P
Pc = Pc−a (T−Tmax) (2) using constant a so that c becomes lower. Steps S3, S4, and S5 are operation parts for preventing the operating oil from becoming high temperature, and for protecting not only the operating oil but also the rubber material of the pipe and the seal material of the hydraulic pump 2 from thermal deterioration. This prevents the discharge oil temperature T from continuously exceeding the maximum discharge temperature Tmax.

In step S6, the target pressure Pc calculated in step S2 or step S5 is reduced to a maximum discharge pressure Pmax set in advance to about 6 to 7 MPa.
Compare with When the determination of (Pc ≦ Pmax) is YES, the process proceeds to step S8. The determination of (Pc ≦ Pmax) is NO, and the target pressure Pc is equal to the maximum discharge pressure Pmax.
If it is higher than x, the flow branches to step S7, and in step S7, the target pressure Pc is reset to the maximum discharge pressure Pmax by the following equation: Pc = Pmax (3), and the flow proceeds to step S8. Steps S6 and S7 are calculation portions for preventing the discharge pressure P from becoming abnormally high and protecting not only the hydraulic pump 2 but also the entire hydraulic device. In step S8, the target pressure Pc calculated up to step S7 is output to the driving device 34.

In FIG. 2, when the air conditioner starts operating at time t1, the required heat quantity Q2 is requested from the air conditioner body to the auxiliary heating device. The arithmetic unit 33 performs an arithmetic operation according to the arithmetic expression (1) according to the flowchart of FIG. 3 (step S2). At this time, since the rotation speed is as low as N1 and the target pressure Pc determined by the above equation (1) is high, the determination of (Pc≤Pmax) is NO (step S6), and the equation (3) Pc = Pma
x) is set (step S7).

From t2 to t4, the required heat quantity is from Q2 to Q
The target pressure Pc linearly decreases to 1, but the target pressure Pc satisfies (Q = Pmax · N1 / k) obtained by modifying (Pmax = kQ / N1) derived from the above equation (1).
Until Pmax is maintained until (P2 = kQ1 /
N1) decreases linearly toward t4. From t5 to t10, the required heat quantity is kept at Q1, and the rotation speed is changed from N1 to N2, N2 to N3, and N3 to N3.
1, but is always controlled to the target pressure Pc determined from the arithmetic expression (1).

As described above, the arithmetic processing according to the required heat amount is continuously performed, and the driving device 34 of the pressure control device 32 that receives the calculation result outputs a driving current to the pressure control valve 31 so that the hydraulic pressure is reduced. The discharge pressure P of the pump 2 is equal to the target pressure P
c is continuously controlled.

Thus, the required amount of heat Q required by the air conditioner body for the auxiliary heating device can be supplied stably and with high accuracy. Therefore, when the engine cooling water guided to the heater core for heating does not become sufficiently high, such as in a cold region or at the time of idling when the engine speed is low, the necessary amount of heat is supplied with good controllability and responsiveness, and sufficient Heating capacity can be secured. Moreover, the auxiliary heating device having the above configuration is
Since the pressure adjusting device 3 and the heat exchange means 4 are incorporated into the hydraulic device of the power steering device in a very simple configuration,
Inexpensive, compact, and easy to mount on vehicles.

Further, the arithmetic unit 33 of the pressure control unit 32
In calculating the target pressure Pc, the maximum discharge temperature Tm
ax and the maximum discharge pressure Pmax are set, and it is possible to prevent the hydraulic device from being damaged by an abnormally high discharge oil temperature T or an abnormally high discharge pressure P.

Next, a second embodiment of the present invention will be described. In the first embodiment, the case where the discharge pressure P of the hydraulic pump 2 is continuously controlled to the target pressure Pc according to the required heat amount Q has been described. However, in the present embodiment, a constant heat amount is intermittently controlled. And the operation of the hydraulic pump 2 is controlled so that the total amount thereof matches the required amount of heat Q. In this case, the signal input to the arithmetic unit 33 of the control device 32 in FIG. 1 is a signal indicating whether or not a heat amount request is input from the required heat amount arithmetic unit 37 of the air conditioner main body, and the discharge oil temperature T which is input from the temperature detection unit 35. There is no signal input from the rotation speed detecting device 36.

FIG. 4 shows a calculation flowchart of the calculation device 33 according to the second embodiment. In FIG. 4, after the start of step S10, in step S11, the necessity of the heat amount request is input from the necessary heat amount calculating device 37 of the air conditioner body to the calculating device 33. In step S12, in response to this, a pressure request is set as necessary or not. In step S13, the discharge oil temperature T is input, and in step S14
Then, the discharge oil temperature T is compared with a maximum discharge temperature Tmax set in advance to about 90 to 100 ° C. (T ≦ T
If the determination of (max) is NO, that is, if the discharge oil temperature T is higher than the maximum discharge temperature Tmax, the flow branches to step S15, and the pressure request is reset to no at step S15. (T ≦
If the determination of Tmax) is YES, step S
Proceed to 16. Then, the necessity of the pressure request determined in step S16 is output to the driving device 34, and the calculation process is terminated.

The drive unit 34 controls ON / OFF of energization of the pressure control valve 31 only in accordance with the necessity of the pressure request signal. The pressure control valve 31 is configured to control the discharge pressure P of the hydraulic pump 2 to a predetermined discharge pressure P ′ set in advance to about 5 to 6 MPa. An amount of heat corresponding to the pressure P 'is given to the discharge oil. The generated heat is used for heating by the discharged oil exchanging heat with engine cooling water in the heat exchanger 41. When the heat quantity is less than the required heat quantity Q required by the air conditioner main body, a signal requesting the heat quantity is input again from the air conditioner main body, and the above operation is performed until the total heat quantity generated matches the required heat quantity Q. repeat.

When the required amount of heat Q is obtained by the operation of the auxiliary heating device, the signal indicating whether the required amount of heat is required in step S11 is denied, and the pressure request signal in step S16 is denied. The energization is stopped.

According to the second embodiment, the required amount of heat required by the air conditioner main body can be generated, and a desired effect can be easily obtained.

In each of the above embodiments, the auxiliary heating device using the hydraulic pump 2 of the power steering device has been described. However, a configuration using a dedicated hydraulic pump may be used.

In each of the above embodiments, the heat exchanger 41 incorporated in the hydraulic device exchanges heat between the working oil and the engine cooling water, and guides the engine cooling water whose temperature has increased to the heater core 42 in the vehicle interior. Although the configuration is adopted, the configuration may be such that the component is directly guided to the heater core 42 in the vehicle interior without using the engine cooling water. Further, the heat exchanger 41 may be arranged between the hydraulic pump 2 and the pressure control valve 31.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an auxiliary heating device according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining an operation of the auxiliary heating device according to the first embodiment, and is a diagram illustrating a relationship between a required amount of heat, a rotation speed, a target pressure, and time.

FIG. 3 is a calculation flowchart of a calculation device according to the first embodiment.

FIG. 4 is a calculation flowchart of a calculation device according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine (internal combustion engine) 2 Hydraulic pump (fluid pump) 3 Pressure adjusting means 31 Pressure control valve 32 Control device 33 Computing device 34 Drive device 35 Temperature detecting device 36 Revolution detecting device 37 Required calorie computing device 4 Heat exchange means 41 Heat Exchanger 42 Heater core 5 Gear box 6 Reservoir

Claims (7)

[Claims] 1. An internal combustion engine for applying a driving force to a vehicle, a fluid pump driven by the internal combustion engine, pressure adjusting means for controlling a discharge pressure of the fluid pump, and a working fluid discharged from the fluid pump And a heat exchange means for performing heat exchange, wherein the pressure adjusting means increases the calorific value of the working fluid by increasing the discharge pressure of the fluid pump, and the heat exchange means increases the heat quantity. A heating device for a vehicle, wherein the heating device receives a heat amount by heat exchange and supplies a heat amount for heating into the vehicle. 2. The vehicle heating apparatus according to claim 1, wherein the pressure adjusting means changes a target value of a discharge pressure of the fluid pump in accordance with a required amount of heat. 3. The vehicle heating apparatus according to claim 1, wherein the pressure adjusting means controls the discharge pressure of the fluid pump to a predetermined pressure while the amount of heat is required. 4. The heating device for a vehicle according to claim 1, wherein the fluid pump is a hydraulic pump of a power steering device. 5. A heat exchanger for transferring heat of a working fluid discharged from the fluid pump to cooling water of the internal combustion engine, and receiving heat for heating from the cooling water of the internal combustion engine. 5. The vehicle heating apparatus according to claim 1, further comprising a heater core introduced into the vehicle. 6. A vehicle heating apparatus according to claim 1, wherein said pressure adjusting means comprises a pressure control valve and a control device for controlling the driving of said pressure control valve. 7. The control device continuously calculates a target value of the discharge pressure of the fluid pump according to a required heat amount, or continuously determines whether or not a pressure request is required according to whether a heat amount request is required. The heating device for a vehicle according to claim 6, further comprising an arithmetic device that performs the calculation.