JPS6364812A - Gas suspension device - Google Patents

Abstract

PURPOSE:To simplify constitution, to reduce the weight of a device, and to improve reliability, by a method wherein, in a gas suspension device, a gas chamber, provided with a hydrogen occlusion alloy, is filled with hydrogen gas, and an alloy is heater or cooled. CONSTITUTION:A ground clearance is lowered by means of a ground clearance sensor. When a lowering amount is detected, an ECU 14 decides a necessary current amount and its direction to feed a current to a hydrogen control device 40 of each suspension device 16. A heat generating module 48 generates heat at a joint on the hydrogen occlusion alloy chamber 46 side by a Peltier effect. The generation of heat causes heating of a hydrogen occlusion alloy 42 through a fin 50 to emit hydrogen gas. Thus, the hydrogen partial pressure of a main chamber 20 is increased to expand the suspension device 16. Conversely, if a ground clearance is increased, a reverse current is fed, heat absorption is caused, and hydrogen is occluded. This constitution enables decrease of the weight of the device, and improvement of reliability.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a suspension device for vehicles, industrial machinery, etc., and more particularly to a gas suspension device that uses gas to change the cushioning characteristics and vehicle height. It is.

[Prior Art] Conventionally, air suspensions using air have been common as gas suspension devices for vehicles and the like. Air suspensions for vehicles are described in detail, for example, in the specification of Japanese Patent Application No. 59-276515 filed by the applicant and in the "Toyota Soarer New Vehicle Manual January 1986" attached to this application. The outline is as follows.

The air suspension system includes an air suspension for each wheel, a near compressor driven by a motor (one for each vehicle), an air dryer to prevent condensation due to phase changes in the air chamber of each air suspension, and an air dryer for the entire system. It is equipped with a solenoid valve that controls the flow of air.

For example, when a vehicle height sensor detects that the vehicle height has decreased, the computer that controls the air suspension system drives the motor to operate the compressor, and the air compressor and each air suspension solenoid valve are activated. By opening the air suspension, a series of controls are performed to supply air to each air suspension and return the vehicle height to its original height.

[Problems to be Solved by the Invention] As described above, in the conventional gas suspension device, in addition to the suspension device having a gas chamber for each wheel, there is also a gas generation source for supplying gas to the suspension device, such as the above example. Therefore, a near compressor, as well as solenoid valves, air dryers, etc., were required. Although one set of these devices is sufficient for a vehicle, it is unavoidable that they add considerable weight, and the presence of long piping and various mechanical valves between these devices and the suspension devices of each wheel makes the system difficult to install. This can add complexity and can cause gas leaks and reduce overall system reliability.

The present invention aims to solve the problems of the prior art described above and to provide a simple and lightweight gas suspension system.

[Means for Solving the Problems] The present invention, which has been made to solve the above problems, changes the volume of the gas chamber and the buffering characteristics by increasing or decreasing the amount of gas in the variable volume gas chamber. The gist of the gas suspension device is a gas suspension device, characterized in that the gas chamber is filled with hydrogen gas, and is equipped with a hydrogen storage alloy and a means for heating or cooling the hydrogen storage alloy. be.

Here, the hydrogen storage alloy refers to a well-known metal or alloy that absorbs hydrogen by reversibly reacting with hydrogen gas to generate a metal hydride, such as LaNi5. Ti-
Fe alloys and the like are known.

These hydrogen storage alloys usually release hydrogen when heated, and store hydrogen, that is, combine it with hydrogen, when cooled.

In addition, particularly when a thermoelectric element is used as a means for heating or cooling the hydrogen storage alloy, it is advantageous for constructing a lightweight and compact gas suspension system. Thermoelectric elements utilize the Peltier effect, a phenomenon in which when a current is passed through a contact between dissimilar metals or semiconductors, heat is generated or absorbed at the contact in addition to Joule heat. It is an element that can be heated and cooled.

FeS! Materials such as z, 5iGe, etc. are known to be useful as such thermal lightning elements. Normally, a large number of such contacts are lined up to perform appropriate heat generation and heat absorption (cooling) as a module.

[Operation] The present invention described above operates as follows. When the heating/cooling means heats the hydrogen storage alloy in response to an external command or the like, the hydrogen storage alloy releases hydrogen and increases the hydrogen partial pressure in the gas chamber. This increases the volume of the gas chamber and also changes the damping characteristics of the suspension device. The expansion of the gas chamber is
For example, when used as a suspension for a vehicle, the height of the vehicle increases.

Conversely, if the hydrogen storage alloy is cooled by heating/cooling means,
The hydrogen storage alloy absorbs hydrogen in the gas chamber and reduces the hydrogen partial pressure. This reduces the volume of the gas chamber and changes the damping properties.

[Example] An example in which the present invention is applied to a vehicle gas suspension system and used for vehicle height adjustment will be shown below.

As shown in FIG. 2, the suspension system of this embodiment includes a vehicle height sensor 12 attached to a vehicle body 10, and a suspension control device (hereinafter referred to as ECU).
14 and a suspension device 16 attached to each wheel 15.

An overall sectional view of each suspension device 16 is shown in FIG. This suspension device 16 is designed as a suspension that can change the spring constant, damping force, and vehicle height, and has a main air chamber 20, a sub air chamber 22, and a variable damping force shock absorber 24 as main components. A bolt 26 is embedded in the upper part of this suspension device 16, and is thereby fixed to the vehicle body 10. Further, the lower part is fixed to the suspension arm of the wheel 15 by the eyeball part 28.

The shock absorber 24 is of a gas-filled type, and the damping force characteristics can be changed by changing the diameter of the orifice through which the oil flows inside the absorber 24. Main air chamber 20 and sub air chamber 2
2 is configured to communicate with the suspension device 16 through three types of passages through a rotary valve 30 provided at the upper part of the suspension device 16. Each of these three types of normal cross-sectional area is
They are large, medium, and small, and switching between these changes the spring constant in three stages.

An enlarged sectional view of the main parts of the suspension device 16 according to the present invention is shown in FIG. The main air chamber 20 includes a cylindrical side wall 32 and a lower diaphragm 34 made of an elastic member.
and a partition wall 36 from the sub-air chamber 22 above. The sub air chamber 22 has a lower part connected to the partition wall 36.
, laterally and upwardly defined by a housing member 38 . As described above, the main air chamber 20 and the sub-chamber 22 are communicated through three types of passages by the rotary valve 30. A bound stopper 31 made of synthetic resin is provided within the main air chamber 20 to reduce the impact of bottoming.

A hydrogen control unit 40 is installed on the side wall 32 of the main air chamber 20.
This hydrogen control section is connected to the ECU 14 by two cords 41. On the side of the main air chamber 20 of the hydrogen control unit 40, a hydrogen storage alloy 46 containing a powdered hydrogen storage alloy 42 and provided with a filter 44 is formed. Here, as the hydrogen storage alloy 42, rare earth metals such as 1aNis, MnNi5. Ti-based TiFe, T
It is possible to use well-known materials such as 1Co, TiMn, and other Ca-based and MO-based materials. A thermoelectric module 48 is provided next to the hydrogen storage alloy 46, and a large number of heat transfer promoting fins 50 protrude from the thermoelectric module 48 into the hydrogen storage alloy chamber 46 and outside the main air chamber 20 on the opposite side. There is.

The thermoelectric module 48 is made of FeSi2.5iGe.

A well-known material using any of materials such as S iGe (GaP) and (Cn, AO)23e can be used. Here, a large number of thermoelectric elements are connected in series in the thermoelectric module 48, and for current in a certain direction, the hydrogen storage alloy chamber 46 side becomes a hot junction, and the main air chamber 2
It is assembled so that the outer side of 0 becomes the cold junction.

Therefore, for the current in the opposite direction, the hydrogen storage alloy chamber 4
The 6th side becomes the cold junction. Furthermore, this thermoelectric module 48
The relationship between the amount of current flowing through the engine, the amount of heat generated, and the amount of heat absorbed is determined in advance and stored in the ECU 14.

The operation of the suspension device 16 of this embodiment having the above configuration will be explained next. When the vehicle height sensor 12 detects that the vehicle height has lowered and the level of the decrease, the ECU 14 uses the amount of current and its direction necessary to restore the vehicle height to the original level, and calculates the amount of current required to restore the vehicle height to the original level. Control device 4
0 in that direction and amount. Hydrogen control device 4
In the thermoelectric module 48 of No. 0, the current causes heat to be generated at the junction of each thermoelectric element on the hydrogen storage alloy chamber 46 side due to the Peltier effect. This heat is transferred to the hydrogen storage alloy 42 through the heat transfer promoting fins 50.

The hydrogen storage alloy and hydrogen are bonded or dissociated by a chemical reaction represented by the following formula.

M (S) + n/2H2 (g) RMHn (S) 10... (1) Here, M is hydrogen storage alloy, H is hydrogen, Q is heat of reaction formation,
(S) represents solid, and (g) represents gas.

In the reaction of equation (1), the equilibrium state is determined by the pressure and temperature of hydrogen gas (Hz (Q)), and the relationship between the above equilibrium pressure (hydrogen dissociation pressure) and temperature for various metals and alloys is shown in Figure 4. is required. In FIG. 4, it is shown that the hydrogen dissociation pressure increases for all metals and alloys as the temperature increases (that is, as you move to the left on the horizontal axis). This is because when the hydrogen storage alloy is heated as described above, (
The reaction in equation 1) progresses from right to left, indicating that hydrogen gas is released from the hydrogen storage alloy and the equilibrium hydrogen partial pressure increases. Furthermore, since the degree to which the hydrogen dissociation pressure changes with respect to the temperature change, that is, the slope of each straight line in Figure 4, is very large, these hydrogen storage alloys can obtain a large change in the equilibrium hydrogen partial pressure even with a small temperature difference. It has the following characteristics.

Temperature of hydrogen storage alloy 42 used in this example -
The relationship between the hydrogen dissociation pressure is stored in the ECU 14 based on the relationship between the amount of current supplied to the thermoelectric module 48 and the increase/decrease in the equilibrium hydrogen partial pressure in the main air chamber 20.
Based on this relationship, the CU 14 determines the amount of current required to raise the vehicle height by a predetermined amount.

In this way, when the hydrogen storage alloy 42 is heated, the hydrogen partial pressure within the main air chamber 20 increases, and the volume of the main air chamber 20 increases by a predetermined amount. That is, since the lower part of the main air chamber 20 is formed by the diaphragm 34 made of an elastic member, the main air chamber 20 itself rises, and the entire length of the suspension device 16 is extended.

As a result, the vehicle height will be restored.

Conversely, when the vehicle height sensor 12 detects that the vehicle height has increased, the ECU 14 causes current to flow in the opposite direction to the thermoelectric module 48 of each wheel. As a result, the joint portion of each thermoelectric element on the side of the hydrogen storage alloy chamber 46 absorbs heat, so the hydrogen storage alloy 42 is cooled via the heat transfer promotion fins 50.
As described above, the hydrogen gas in the main air chamber 20 is absorbed to lower the hydrogen partial pressure. This lowers the vehicle height and realizes vehicle height adjustment.

In this way, this embodiment does not require a conventional heavy gas pressure generating device such as a compressor, and can change the volume of the main air chamber 20, that is, change the vehicle height, using a lightweight and compact device. Can be done. Furthermore, since there are no moving parts, let alone piping or valves for gas, the system is extremely reliable. Furthermore, as mentioned above, since the hydrogen storage alloy 42 shows a large change in hydrogen dissociation pressure with a slight temperature change,
The thermoelectric module 48 has the advantage that the heat generation (or absorption) capacity can be small, and the power supply for it can also be small.

In the above embodiment, the thermoelectric module 48 was used to heat and cool the hydrogen storage alloy 42, but the same vehicle height adjustment function can also be achieved by heating with an ordinary electric heater and cooling with circulating water. It can be demonstrated.

[Effects of the Invention] By using the gas suspension device using the hydrogen storage alloy according to the present invention, the weight of the conventional gas suspension device system can be significantly reduced, and the reliability can also be significantly improved. can.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of a suspension device to which an embodiment of the present invention is applied, Fig. 2 is a block diagram of the entire suspension system of the embodiment, and Fig. 3 is a sectional view of the entire suspension system of the embodiment. , FIG. 4 is a graph showing the relationship between temperature and hydrogen dissociation pressure for various metals and alloys. 14...Suspension control device 16...Suspension device 20...Main air chamber 40...Hydrogen control device 42...Hydrogen storage alloy 48...Thermoelectric module

Claims (1)

[Scope of Claims] 1. A gas suspension device that changes the gas chamber volume and buffer characteristics by increasing or decreasing the amount of gas in the gas chamber whose volume is variable, the gas chamber being filled with hydrogen gas, and A gas suspension device comprising a hydrogen storage alloy and means for heating or cooling the hydrogen storage alloy. 2. The gas suspension device according to claim 1, wherein the heating or cooling means is a thermoelectric element.