JPH03253788A - Safety device of squeezing-up type fluid pump - Google Patents

Abstract

PURPOSE:To improve operativity and reliability of work by actuating an alarm means in the case when a vacuum pump does not reach low pressure within a certain period of time due to damages to a pumping tube while stopping the vacuum pump when it reaches specified low pressure by the time when a timer reaches the certain period of time. CONSTITUTION:A fluid pump 1 loaded on a car forcibly delivers concrete in a hopper 5 to a concrete placing site through a piping 7 by way of pressing and rolling a roller (not illustrated) on a pumping tube 4 extensively provided in a casing 3. The inside of the casing 3 is decompressed down to a certain low pressure by a vacuum pump 8 through a piping 9. In this case, a pressure switch 10 to detect pressure inside the casing 3 is provided, and when the certain low pressure is detected before the start of the vacuum pump 8, the vacuum pump 8 is stopped and simultaneously, in the case when it does not come down to low pressure within the certain period of time due to damages to the pumping tube 4, an alarm means is actuated.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention is used in the field of a squeeze-type fluid pump that uses a vacuum pump to create a low pressure inside a casing.

(b) Conventional technology The conventional squeezing type fluid pump is 1ft14
As disclosed in No. 1, a pumping tube is installed inside a sealed casing, and this pumping tube is
The fluid is pumped by the two rollers pressing and rolling. Furthermore, by lowering the pressure inside the casing using a vacuum pump, the restoring force of the pumping tube is increased and the pumping efficiency is increased.

By the way, since the vacuum pump disclosed above is linked to a fluid pump, it is operated even when the pressure inside the casing is low, which has the disadvantage of requiring unnecessary labor. A manually operated vacuum pump is used.

(C) (d) Problems to be Solved by the Invention However, when operating the vacuum pump, it is necessary to operate it while looking at the pressure gauge, which makes the operation complicated and may cause the pumping tube to burst. There is a problem in that even if a leak occurs in the casing, the operator has no means to detect it and continues to operate the vacuum pump.

Therefore, the present invention automatically stops the vacuum pump when the inside of the casing reaches a predetermined low pressure, and also alerts the operator if there is a leak in the casing, thereby improving work efficiency. The present invention provides a safety device for a squeeze-type fluid pump.

Means for Solving the Problems The present invention provides a pumping tube in a sealed casing, presses and rolls the pumping tube on the pumping tube with a roller, and lowers the pressure inside the casing with a vacuum pump. In a squeeze-type fluid pump for pumping fluid, a timer control means for maintaining the operating state for a certain period of time after the vacuum pump is activated, and a pressure control means for stopping the vacuum pump when the inside of the casing reaches a predetermined low pressure; The present invention relates to a safety device for a squeeze-type fluid pump, which includes an alarm means that issues an alarm if the pressure control means does not operate within a predetermined period of time set by the timer control means.

(e) Activate the vacuum pump and activate the timer control means.

When the inside of the casing reaches a predetermined low pressure by the time the timer control means reaches a certain time, the pressure control means detects the low pressure and stops the vacuum pump.

On the other hand, if the low pressure is not reached within a certain period of time due to damage to the pumping tube, leakage of the casing, etc., the timer control means activates the V alarm means to notify the work shore that there is a malfunction.

(f) Embodiment Hereinafter, embodiments of the present invention will be explained with reference to the drawings. (1) is a fluid pump for pumping concrete, etc. mounted on a vehicle body (2); ) and install the pumping tube (4) inside the tube (4).
A roller (not shown) presses and rolls on the top.

The suction side of the tube (4) is connected to the discharge pipe (8) of the hopper (5) on the vehicle body (2), and the discharge side of the tube (4) is connected to the pipe (7), The concrete inside is pumped to the pouring site through a fluid pump (1) and piping (7).

(8) is a low pressure inside the casing (3) (approximately 600 to 88
0 mmt (g), the vacuum pump (8) is provided close to the fluid pump (1), and the pipe (8) from the vacuum pump (8) is connected to the casing (3). ing.

A pressure switch (10) that detects the pressure inside the casing (3) is provided in the middle of the pipe (8), and the pressure switch (10) has an upper pressure switch PS1 that detects an upper limit low pressure (approximately Ei 80 mmHg) and a lower limit pressure switch PS1 that detects the upper limit low pressure (about Ei 80 mmHg). Low pressure (approximately 600m
(mHg) and a lower limit pressure switch PS2 that detects the pressure (mHg).

(11) is an operation panel fixed to a part of the casing (3).

Next, the electric circuit will be explained using Figure 2.The main circuit (1
2) and the control circuit (13), and the main circuit (12)
) is provided with a main switch (14), a normally open type first relay switch r1, and a vacuum pump (3) in series.

The control circuit (13) is provided with a switch (15) linked to the engine key and a changeover switch (16), and the changeover switch (16) is connected to an automatic circuit (17), a means circuit (
18) and the stop position.

The manual circuit (18) includes a first relay R located in parallel.
1 and a lamp (19) that indicates that the vacuum pump (mountain) is in operation.
and is connected to.

From the automatic circuit (17) are an i-th circuit (20), a second circuit (21), a fluid pump operation circuit (22), an alarm circuit (23), a first detection circuit (24), and a second detection circuit ( 2
5) is branched.

The first circuit (20) includes a normally closed timer relay switch t and a normally open color brush 2 relay switch r2 connected in series, and is connected to the first relay R1 and the lamp (19).

The second circuit (21) is a normally closed fourth relay inch r4.
A normally closed color brush 5 relay switch r5 and a second relay R2 are provided in series, a normally open color brush 2 relay switch r2 is provided in parallel with the fifth relay switch r5, and the second relay R2
A timer relay T is provided in parallel with the timer relay T, and a timer relay switch t is activated after a certain period of time (about 6 minutes) has passed after the timer relay T is energized. The fixed time can be set by operating the vacuum pump (8) to
) so that it takes longer than the time (approximately 5 minutes) to reach low pressure.

The fluid pump operating circuit (22) includes a normally closed color brush 3 relay switch r3 and a drive device (26) for the fluid pump (1) in series, and a manual switch (27) in parallel with the third relay switch r3. This is provided.

The alarm circuit (23) is provided with a normally open timer relay switch t and a buzzer BS in series, and a third relay R3 and a lamp (28) are provided in parallel with the buzzer BS.

The first detection circuit (24) is provided with a fourth relay R4 and an upper limit pressure switch PS1 in series, and the second detection circuit (25
) is provided with a fifth relay R5 and a lower limit pressure switch PS2 in series.

The present invention has the above-mentioned configuration, and its operation will be explained next. When the engine key is started, the switch (15) is set to "closed" and the main switch (14) of the main circuit (12) is set to "closed". do. At the same time, the selector switch (16) is switched to the automatic circuit (17) side. As a result, the second relay R2 of the second circuit (21) is energized, and the first
1/-R3 is energized, the vacuum pump (3) is started, and the pressure inside the casing (3) is reduced. At that time, the lamp (19) on the operation panel (11) lights up and the vacuum pump (
The timer relay T
is also energized.

When the vacuum pump (g) is started and the inside of the casing (3) reaches the lower limit low pressure before the fixed time set by the timer relay T, the lower limit pressure switch PS2 becomes "closed" and the switch r2 that energizes the fifth relay R5 is turned on. Since the second relay R2 is self-maintained, the energization to the second relay R2 is maintained.

If the pressure reduction continues, the inside of the casing (3) will reach the upper limit low pressure before the fixed time (approximately 6 minutes) set by the timer relay T, and the intraocular pressure switch PS1 will become "closed" and the fourth relay R4 will be turned on. Turn on electricity. As a result, the second relay R2 is de-energized, the first relay R1 is also de-energized, and the vacuum pump (8, n) is stopped.
Even if the internal pressure of the vacuum pump changes, the vacuum pump remains stopped until the lower limit pressure is reached.

Next, to explain the case where the pumping tube is damaged or there is a leak in the casing, both the switch (15) and the main switch (14) are turned on as before, and the changeover switch (16) is turned on. ) to the automatic circuit (17). This will allow the vacuum pump (8)
starts.

By the way, even if the vacuum pump (8) is operated, the pressure inside the casing (3) is not reduced or the pressure reduction speed is slow, so a certain period of time set by the timer relay T has elapsed before the pressure is detected by the pressure switch (10). , the first relay R1 is de-energized and the vacuum pumps stop. At the same time, the timer relay switch t of the alarm circuit (23) is turned on.
When the buzzer BS sounds, the lamp (28) lights up to alert the worker.

At this time, the power to the drive device (26) (g) of the fluid pump (1) is removed, and the fluid pump (1) also stops. However, if you operate the switch (27), the fluid pump (1)
It is possible to drive

If you want to operate the vacuum pump manually, just switch the selector switch (16) to the manual side, and press the pressure switch (16) to the manual side.
0), the vacuum pump Φ can be operated regardless of the

Effects of the Invention As described above, the present invention automatically stops the vacuum pump when the pressure control means reaches a predetermined low pressure, and the pressure control means detects the predetermined low pressure within a fixed time of the timer control means. If not, the alarm means will issue an alarm to notify the operator of the failure of the fluid pump, making it extremely easy to operate the inside of the casing to a low pressure, and also detect failure of the fluid pump. I can do it. Further, since the fluid pump is not used in a malfunctioning state, the fluid pumping operation can be carried out safely.

[Brief explanation of drawings]

FIG. 1 is an overall diagram, and FIG. 2 is an electrical circuit diagram. (1) is a fluid pump, (3) is a casing, (4) is a pumping tube, (8) is a vacuum pump, and (1O) is a pressure switch.

Claims (1)

[Claims] A squeeze-type fluid pump that pumps fluid by providing a pumping tube in a sealed casing, pressing and rolling the pumping tube with a roller, and lowering the pressure inside the casing with a vacuum pump. a timer control means for maintaining the vacuum pump in an operating state for a predetermined time after activation; a pressure control means for stopping the vacuum pump when the inside of the casing reaches a predetermined low pressure; and a pressure control means for operating within the predetermined time of the timer control means. A safety device for a squeeze-type fluid pump comprising an alarm means for issuing an alarm if the pump fails to do so.