JPH02239394A - Syrup pump for automatic vending machine - Google Patents

Abstract

PURPOSE:To make a syrup discharge quantity correct and to improve sefety by counting pulse signals caused by the rotation of a motor by means of a control part, comparing the value of the signals with a prescribed value, forward and backward rotating the motor, and stopping conduction when the pulse signals are not inputted for a prescribed time. CONSTITUTION:When a control part 22 detects a syrup discharge instruction 23, the part 22 forward and backward rotates a motor 15, a screw shaft 16 is rotated, a nut member 17 advances, pushes a diaphragm 3 through a transmitting member 12, and the syrup is discharged. Simultaneously the control part 22 counts the pulse signals from a photo-interrupter 20b, when the value amounts to the set prescribed value, the forward rotation is stopped, and the motor 15 is backward rotated until a microswitch 19 detects the return of the member 17. In addition, the control part 22 stops the conduction to the motor 15 when the pulse signals are not detected for the prescribed time during the forward driving. Thus the discharge quantity of the syrup can be made correct, and the safety at the time of an accident can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a syrup pump used for dispensing syrup, etc. in a drinking water vending machine.

2. Description of the Related Art A syrup pump of this type is constructed as shown in FIG. A diaphragm 3 is sandwiched between a pump body 1 and a cover 2, and the pump body 1 and cover 2 are integrally connected. A pump body 1 is provided with a suction port 4 and a discharge port 5, and check valves 6 and 7 are provided respectively. A drive shaft 9 is rotatably attached to a support frame 8 fixed to the outside of the cover 2, and the drive shaft 9 is driven by a motor (not shown) attached to the back surface of the support frame 8. A cam 1G is attached to the drive shaft 9, and a crank bin is fixed to this cam 10! l and
A transmission member 12 fixed to the diaphragm 3 is connected to a pin 13 fixed by a link 14.

Therefore, when the drive shaft 8 is rotationally driven by the motor, the cam 1
0 rotates and the transmission member l2 reciprocates in the eight directions of the arrows via the link l4, and when the diaphragm 3 moves backward in the direction of the arrow B, it sucks in syrup from the suction port 4, and the diaphragm 3 moves the sucked syrup in the direction of the arrow. When moving forward in the C direction, it is discharged from the discharge port 5.

Problems to be Solved by the Invention In such a conventional configuration, the rotation time of the motor per sales operation is constant, and the amount of syrup discharged is preset to a required amount by changing the shape of the cam 10.

However, such mechanical setting of the syrup discharge amount is troublesome and has poor workability.

SUMMARY OF THE INVENTION An object of the present invention is to provide a syrup pump that can electrically adjust the amount of syrup discharged.

Means for Solving the Problems The syrup bomb of the present invention is a syrup pump that transports syrup by reciprocating a diaphragm, in which a drive unit for reciprocating the diaphragm is driven by a screw shaft rotatably driven by a motor, and the screw shaft. a nut member that is screwed into the diaphragm and is slidable in the direction of the reciprocating movement of the diaphragm; and a transmission member that extends in the direction of the reciprocating movement of the diaphragm and has one end connected to the diaphragm and the other end connected to the nut member. and a rotation detection means for outputting a pulse signal in accordance with the rotation of the screw shaft, and a rotation detection means for driving the diaphragm until the pulse signal generated from the rotation detection means matches a prescribed number of pulses corresponding to the required amount of syrup. The present invention is characterized by comprising a control section that drives the motor in normal rotation and turns off the power to the motor if a pulse signal from the rotation detection means is not detected for a predetermined period of time or more while the motor is being driven.

According to this configuration, when the motor is driven in normal rotation, the screw shaft rotates and the nut member moves forward in a direction approaching the diaphragm. When the nut member moves forward, for example, the central portion of the diaphragm is pushed out via the transmission member, and the syrup is gradually pushed out. When the motor is rotated, pulse signals are generated one after another from the rotation detecting means as the motor rotates. The control section is
The pulse signals are counted and compared with a specified value, and when the counted value reaches the specified value, the motor is driven in reverse, and the center of the diaphragm begins to retreat. This retraction draws syrup into the syrup pump.

If an abnormal situation such as the motor locking occurs while the motor is being driven, the control unit detects the occurrence of this abnormal state since the pulse signal is not input for a specified period of time, and turns off the power to the motor. Prevent motor overheating.

EXAMPLE Hereinafter, the syrup pump of the present invention will be explained based on one example. Components having the same functions as those of the conventional example shown in FIG. 2 will be described with the same reference numerals.

FIG. 1 shows a syrup pump according to the invention. A screw shaft l6 is provided at the rear of the cover 2 and is rotationally driven by a motor l5. A nut member l7 is screwed onto the screw shaft 16 and is slidable in the direction of reciprocating movement of the diaphragm 3 (in the direction of arrow D). Reference numerals 18a and 18b are guides for preventing rotation of the nut member l7. Transmission member! 2, one end is connected to the diaphragm 3, the protrusion 17a of the nut member 17 is engaged with the hole 12a bored at the other end, and the transmission member I2 connects the nut member l7 and the diaphragm 3. There is. 19
is a microswitch as a return detection means for detecting that the nut member l7 has reached the initial position shown by the imaginary line;
20a and 20b are a slit plate and a photointerrupter as rotation detection means, which are connected to the casing 2 together with the motor 15.
1, and when the slit plate 20a rotates with the rotation of the motor 15, the photointerrupter 20b reads the passage of the slit of the slit plate 20a and outputs a pulse signal. Reference numeral 22 denotes a control unit that determines the time period for which the motor 15 is energized and the direction in which it is energized based on the output signal of the microswitch I9 and the output signal of the photointerrupter 20b.

Next, the configuration of the control section 22 will be explained in accordance with the order of operation. When the control unit 22 detects the syrup dispensing instruction 23, it drives the motor 15 in normal rotation, counts the number of pulse signals from the photointerrupter 20b, and compares it with a specified value set according to the required amount of syrup. Here, the occasional count value is N. ．． Assuming that the specified value set according to the required amount of syrup is NR, when Ns≧NR is detected, the normal rotation drive is ended. Then, the motor I5 is driven in the reverse direction until the microswitch l9 detects the return of the nut member l7.

In this way, the required amount of syrup is discharged from the discharge port 5 every time the syrup dispensing instruction 23 is detected.

Here, each time the ejection is completed, it returns to the initial position, so the amount of ejection each time is accurate.

Furthermore, the control unit 22 counts the interval of pulse signals generated from the photointerrupter 20b while driving the motor 15 in forward or reverse rotation, and if the next pulse signal is not detected even after a specified time has elapsed, The power supply to the motor 15 is terminated and the sales columns using this syrup pump are switched to the sold-out state, thereby eliminating accidents caused by overheating of the motor 15 and increasing safety.

In the above embodiment, the rotation detecting means was explained using the slit plate 20a and the photointerrupter 20b as an example, but in this case, the rotation detecting means is composed of a gear attached to the output shaft of the motor l5 and an outer circumference of the gear. A magnetic sensor supported from the fixed side so as to be located close to the fixed side, and a permanent magnet for generating a bias magnetic field attached to the fixed side. The same applies to a pulse generator that detects the rotation of the motor 15 by changing the magnetic flux.

Effects of the Invention As described above, according to the configurations described in each claim, in a syrup bomb that transports syrup by reciprocating a diaphragm, the drive unit that reciprocates the diaphragm is
a screw shaft rotationally driven by a motor; a nut member screwed onto the screw shaft and slidable in the direction of the reciprocating movement of the diaphragm; and a nut member extending in the direction of the reciprocating movement of the diaphragm and having one end connected to the diaphragm. , a transmission member whose other end is connected to the nut member, a rotation detection means that outputs a pulse signal in accordance with the rotation of the screw shaft, and the pulse signal generated from the rotation detection means is necessary for the outward path to drive the diaphragm. Drive the motor in normal rotation until the number of pulses reaches a specified number according to the amount of syrup,
The structure includes a control section that turns off the power to the motor if no pulse signal is detected from the rotation detection means for a predetermined period of time during forward rotation, so the amount of syrup dispensed can be adjusted simply by changing the specified number of pulses in the control section. can be varied,
Furthermore, in the event that the motor is locked, the power supply to the motor can be quickly stopped, thereby avoiding various accidents caused by overheating of the motor, thereby improving safety.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of the syrup pump of the present invention;
FIG. 2 is a block diagram of a conventional syrup pump. 3...Diaphragm, 4...Suction port, 5...Discharge port, l2...Transmission member, 15...Motor, 1B...
・Screw shaft, 17... Nut member, 19... Micro switch [return detection means], 20a, 20b... slit plate, photointerrupter [rotation detection means], 22.
...Control unit.

Claims (1)

[Claims] 1. In a syrup pump that transports syrup by reciprocating a diaphragm, a drive unit that reciprocates the diaphragm is screwed into a screw shaft that is rotationally driven by a motor, and the direction of the reciprocating movement of the diaphragm is screwed to the screw shaft. a nut member that is slidable in a direction; a transmission member that extends in the direction of the reciprocating movement of the diaphragm and has one end connected to the diaphragm and the other end connected to the nut member; and a transmission member that transmits a pulse signal as the screw shaft rotates. The motor is driven in normal rotation until the pulse signal generated from the rotation detection means matches a predetermined number of pulses corresponding to the required amount of syrup, and the motor is driven in normal rotation to drive the diaphragm. A syrup pump comprising a control section that turns off power to a motor when a pulse signal from a rotation detection means is not detected for a period of time or more.