JP3328992B2 - LPG residual quantity warning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an industrial vehicle such as a forklift using LPG (liquefied petroleum gas) as a fuel, and the LPG in an LPG cylinder mounted on the vehicle is reduced to replace or fill the cylinder. The present invention relates to an LPG remaining amount warning device for warning that time is approaching.

[0002]

2. Description of the Related Art As a conventional LPG remaining amount warning device, a pressure switch system and a level sensor system are generally used.
The former pressure switch method uses an LPG as shown in FIG.
A pressure switch 32 is mounted in the middle of a fuel supply line 31 connecting the cylinder and the regulator.
The warning light (or buzzer) 33 is turned on by the on-action of. That is, the pressure switch 32 applies a pressure of the pressure chamber 35 communicating with the fuel supply pipe 31 to one surface of the diaphragm 34 having the movable contact 32a, and applies a pressing force of the spring 36 to the other surface. The diaphragm 34 is pushed by the spring 36 in response to the pressure drop due to the decrease of the LPG, and the movable contact 32
a contacts the fixed contact 32b and supplies the power of the battery 37 to the warning light 33.

On the other hand, the latter level sensor system uses an LPG
A level sensor using a float is provided on the cylinder, and the gas amount is displayed by a level meter attached to the LPG cylinder so as to be mechanically linked with this level sensor, or the mechanical displacement of the level sensor is converted into an electric signal. The gas amount is displayed by a level meter attached to the instrument panel in front of the driver's seat (or a warning is given by a warning light or a buzzer).
No. 88828 can be mentioned.

[0004]

However, in the case of the former pressure switch method, it is difficult to specify the operating time of the vehicle based on the remaining amount after the vapor pressure of the LPG drops to the set value and the pressure switch is activated. There is a problem with the point. That is,
The vapor pressure of LPG varies depending on the LPG component and the LPG solution temperature.
The higher the liquid temperature, the higher. Therefore, the remaining amount of LPG at the time when the pressure switch is operated is not constant, and as a result, there is a problem that the fuel runs out earlier than expected and the vehicle cannot travel to the cylinder storage area.

On the other hand, in the case of the latter level sensor system,
Although there is no problem like the above pressure switch method, LP
Since it is necessary to provide a level sensor for each G cylinder, the LPG cylinder lacks marketability because it is a special one and the cost is high, and a specific LPG cylinder with a level sensor is provided. The problem is that it can only be used.

Accordingly, the present invention has been made in view of the above-mentioned problems, and
The technical problem to be solved is to provide an LPG remaining amount warning device that installs a sub-tank separately from the G cylinder for remaining amount detection and provides a constant remaining amount at the time of warning and regardless of the type of cylinder used. I do.

[0007]

Means for Solving the Problems In order to solve the above problems, the present invention is configured as follows. That is, the invention of claim 1 is an LPG remaining amount warning device for warning that the LPG of the LPG cylinder has decreased and is approaching the cylinder replacement time or the gas filling time, wherein the LPG of the LPG cylinder is supplied in a liquid state. A sub-tank is installed in the LPG supply path, and the sub-tank is provided with a warning light or a level sensor that outputs a signal for operating a warning buzzer when the liquid level in the tank has dropped to a set level. It is characterized by that. According to a second aspect of the present invention, in the LPG remaining amount warning device according to the first aspect, the level sensor converts a float corresponding to the liquid level of the sub-tank and a mechanical displacement amount of the float into an electric signal and outputs the electric signal. A potentiometer; and a control device for receiving an output signal of the potentiometer and turning on a power supply circuit of the warning light or the warning buzzer when the liquid level falls to a set level.

[0008]

The LP according to the first aspect of the present invention configured as described above.
In the remaining G warning device, the liquid level in the sub-tank remains at the highest level while the liquid phase exists in the LPG cylinder. The liquid level inside drops. When the liquid level in the sub-tank drops, the level sensor detects the drop, and when the liquid level drops to the set value, a warning light or a buzzer is activated to approach the cylinder replacement time or gas filling time. Warn that. That is, the present invention is a method for detecting the liquid level,
The remaining amount of LPG at the time of detection is always constant irrespective of the components and the liquid temperature, and any LPG cylinder can be used.

Further, in the LPG residual quantity warning device according to the present invention, a float is used as a level sensor;
Because a potentiometer linked to this is used,
The warning time can be arbitrarily selected.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a simplified diagram showing an LPG fuel supply system and an LPG remaining amount warning device applied to a forklift. The LPG in the LPG cylinder 1 is sent to a regulator 3 through a high-pressure hose 2 as a fuel supply path, a filter and a solenoid valve (not shown) as shown by an arrow, and then an LPG carburetor through a main fuel supply pipe 4. 5 and is mixed with air and supplied to the engine 6.

In general, the LPG cylinder 1 is mounted on a counterweight at the rear of the vehicle body or on a rear pillar or the like in a horizontal position, and is arranged at a position higher than downstream equipment to which LPG is supplied. Therefore, LPG is supplied in a liquid phase between the LPG cylinder 1 and the regulator 3, and is vaporized by passing through the regulator 3.

A sub-tank 7 for detecting the remaining amount of LPG is installed at an arbitrary position in the fuel supply path connecting the LPG cylinder 1 and the regulator 3, in the present embodiment, near the exit of the LPG cylinder 1. I have. This sub-tank 7 has an LPG inlet 9 provided with a manual open / close valve 8 and an LPG inlet provided with a manual open / close valve 11 of the LPG cylinder 1.
Connected to the outlet 12 and the hose 13 and
An outlet 10 is connected to the high-pressure hose 2.

A take-out siphon 14 is connected to the inner end of the cylinder of the LPG take-out port 12, and the suction port of the take-out siphon 14 reaches the cylinder bottom of the LPG cylinder 1 installed horizontally. And the sub tank 7
The installation position is determined so that it is lower than the suction port of the take-out siphon 14. Therefore, the sub tank 7
Is kept at the highest level until the liquid in the LPG cylinder 1 is exhausted and the whole becomes a gas phase, and then falls.

The sub-tank 7 for detecting the remaining LPG has a level sensor 15. This level sensor 15 is a float 16 that moves up and down in response to the liquid level in the sub tank 7.
And a potentiometer 17 that converts the mechanical displacement of the float 16 into an electrical displacement and outputs the displacement to the control device 18.

On the other hand, a warning light (or buzzer) 19 which is activated when the liquid level in the sub-tank 7 drops to a certain level and issues a warning is installed, for example, on an instrument panel (not shown) in front of the driver's seat. . A switch 20 that is turned on and off by the control device 18 is inserted into the energizing circuit of the warning light 19. When the switch 20 is turned on, the energizing circuit using the battery 21 as a power source is turned on.

That is, in the LPG residual quantity warning device according to the present embodiment, the sub-tank 7 is installed separately from the LPG cylinder 1 and the liquid level in the sub-tank 7 is detected to determine the residual quantity. It is configured. Therefore, the liquid level in the sub tank 7 is maintained at the maximum level until the liquid in the LPG in the LPG cylinder 1 runs out, and when the liquid runs out, the liquid level gradually drops thereafter. Then, when the float 16 descends as the liquid level falls, the mechanical displacement is converted into an electric displacement by the potentiometer 17 and input to the control device 18. The control device 18 compares the input signal (voltage) with a preset reference voltage, and when the input signal reaches the reference value, outputs a drive signal to the switch 20 of the energizing circuit of the warning light 19, and the switch 20 Turn on.

That is, when the liquid level in the sub tank 7 decreases to a predetermined set level, the warning lamp 19 is turned on. Thus, the operator can know that the replacement time (or filling time) of the LPG cylinder 1 is approaching. In this case, the remaining amount of LPG in the sub tank 7 when the warning light is turned on, which is determined based on the liquid level, is always constant regardless of the components and the liquid temperature, that is, regardless of the level of the LPG vapor pressure.

Therefore, the operator can carry out appropriate cylinder replacement (filling) based on accurate information by knowing in advance the possible travel distance after the warning light 19 is turned on. In the LPG residual quantity warning device of the present embodiment, the sub tank 7 is controlled by the potentiometer 17.
The liquid level change of the switch 20 is continuously taken into the control device 18, and the control device 18 controls on / off of the switch 20, so that the operation timing of the switch 20, that is, the lighting timing of the warning lamp 19 is freely set and turned on. The possible travel distance can be changed.

Next, another embodiment of the present invention will be described with reference to FIG. In this embodiment, a float 16 which descends in response to a liquid level drop of the sub tank 7 and a switch 20 for turning on a warning light 19 are mechanically connected by a lever or a link 22 to turn the switch 20 on and off. It was done. That is, in this embodiment, the switch 20 is directly operated by the mechanical displacement of the float 16, and the other configuration is the same as that of the above-described embodiment. Therefore, in this embodiment, since the potentiometer 16 and the control circuit 18 can be omitted as compared with the above-described embodiment, it is advantageous in that the structure can be simplified and the cost can be reduced.

In the illustrated embodiment, the case where the sub-tank 7 is installed in the vicinity of the outlet of the LPG cylinder 1 has been described. No problem.

[0021]

As described in detail above, according to the present invention,
Since the LPG remaining amount is detected by the level sensor, the remaining amount can be accurately detected regardless of the LPG component and without being affected by the liquid temperature. Any LPG cylinder can be used because it is performed by a separate sub tank. Also, since the LPG remaining amount after the warning is constant,
The problem that the running distance based on the remaining amount is stabilized and the fuel tank runs out of fuel on the way to the cylinder storage area is solved.

[Brief description of the drawings]

FIG. 1 shows an LPG remaining amount warning device and an LPG according to an embodiment of the present invention.
FIG. 2 is a simplified explanatory diagram showing a PG fuel supply system.

FIG. 2 is a simplified explanatory view showing an LPG remaining amount warning device according to another embodiment of the present invention.

FIG. 3 is an explanatory view showing a conventional pressure switch type LPG remaining amount warning device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... LPG cylinder 3 ... Regulator 7 ... Subtank 15 ... Level sensor 16 ... Float 17 ... Potentiometer 18 ... Control device 19 ... Warning light (buzzer) 20 ... Switch for energization

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60K 15/073 B60K 15/077 B60K 15/10

Claims (2)

(57) [Claims] An L warning that the LPG of the LPG cylinder has decreased and is approaching the cylinder replacement time or gas filling time.
A PG remaining amount warning device, wherein the LPG of the LPG cylinder is supplied in a liquid state.
An LPG having a sub-tank installed in the G supply path and a level sensor for detecting that the liquid level in the tank has dropped to a set level and outputting a warning light or a signal for operating a warning buzzer in the sub-tank. Low battery warning device. 2. The level sensor according to claim 1, wherein said level sensor comprises a float responding to the liquid level of said sub-tank, and a potentiometer for converting a mechanical displacement of said float into an electric signal and outputting said electric signal. 2. The LPG remaining amount warning device according to claim 1, further comprising a control device that turns on a current supply circuit of the warning light or the warning buzzer when the liquid level falls to a set level after being taken.