JPH02227794A - Syrup pump for automatic vending machine - Google Patents

Abstract

PURPOSE:To electrically regulate a syrup discharge quantity by providing a control part which forward drives a motor until the number of pulse signals corresponds to the prescribed number of pulses according to a necessary syrup quantity. CONSTITUTION:When a control part 22 detects a syrup discharging instruction 23, a motor 15 is forward driven, the number of the pulse signals from a photo interpreter 20b is counted, and the part 22 compares the number with a prescribed value set according to the syrup necessary quantity. When the occational counted value is set at NS, and the prescribed value set according to the syrup necessary quantity is set at NR, NS >= NR is detected, and the forward driving is completed. Next a motor 15 is backward driven until a microswitch 19 detects the restoration of a nut member 17. In such a way, whenever the instruction 23 is detected, the necessary quantity of the syrup is discharged from a discharging port 5. Thus the syrup discharge quantity can be made variable only by altering the setting of the number of the prescribed pulses in the control part 22.

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 10 is attached to the drive shaft 9, and a crank pin U fixed to the cam IO and a pin 13 fixed to a transmission member 12 fixed to the diaphragm 3 are connected by a link 14.

Therefore, when the drive shaft 9 is rotationally driven by the motor, the cam l
O rotates and the transmission member 12 moves in the direction of arrow A via the link 14.
When the diaphragm 3 moves backward in the direction of arrow B, syrup is sucked in from a suction port 4, and when the diaphragm 3 moves forward in the direction of arrow C, it is discharged from a discharge port 5.

Problems to be Solved by the Invention In such a conventional configuration, - the rotation time of the motor per vending 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 pump of the present invention is a syrup pump that transports syrup by reciprocating a diaphragm, in which a drive section 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. It is characterized by comprising a control section that drives the motor in forward rotation.

Further, in the syrup pump according to claim 1, return detection means is provided for detecting that the nut member has returned to the initial position, and the return detection means detects the nut member during the return path in which the control section drives the diaphragm. The present invention is characterized in that the motor is configured to be driven in the reverse direction until the motor is driven in the reverse direction.

According to the structure of each claim, when the motor is driven to rotate normally, the screw shaft rotates and the nut member moves forward in a direction approaching the diaphragm. When the nut member moves forward, the central portion of the diaphragm, for example, 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 unit counts the pulse signals and compares them with a specified value, and when the counted value reaches the specified value, drives the motor in reverse, and the center portion of the diaphragm begins to retreat. This retraction draws syrup into the syrup pump.

According to the second aspect of the present invention, the reverse rotation drive is terminated when the return detection means detects the return of the nut member.

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 16 that is rotationally driven by a motor 15 is provided at the rear of the cover 2 . A nut member 17 that is slidable in the direction of reciprocating movement of the diaphragm 3 (in the direction of the arrow) is screwed onto the screw shaft 1B. Reference numerals 18a and 18b are guides for preventing rotation of the nut member I7. The transmission member 12 is connected to the diaphragm 3 at one end, and the protrusion 17a of the nut member 17 engages with a hole 12a formed at the other end, so that the transmission member I2 connects the nut member 17 and the diaphragm 3. ing. 1
Reference numeral 9 denotes a microswitch 20a as return detection means for detecting that the nut member 17 has reached the initial position shown by the imaginary line.

Reference numeral 20b denotes a slit plate and a photointerrupter as rotation detection means, which are housed together with the motor 15 in the casing 21. As the motor 15 rotates, the slit plate 20
When a rotates, the photointerrupter 20b reads the passage through 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 19 and the output signal 61 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, if the occasional count value is Ns, and the specified value set according to the required amount of syrup is N8, then Ns≧NR is detected and the normal rotation drive is ended. Then, the motor 15 is driven in the reverse direction until the microswitch 19 detects that the nut member 17 has returned.

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, the ejector returns to the initial position, so the amount of ejection each time is accurate.

In the above embodiment, when the microswitch 19 serving as a return detection means detects the nut member 17, the control unit 22 ends the reverse drive of the motor 15, but this is done by applying a pulse of the specified value N□ from the normal rotation end position. The reverse rotation driving of the motor 15 may be terminated when the control unit 22 detects the signal. However, if forward and reverse rotation driving is dependent only on the management of the pulse signal of the specified value N7, the nut member 17 may not return to the initial position accurately, and in this case, the amount of error will accumulate. During long-term use, there is a possibility that the period in which forward rotation can be driven will be less than the counting period of the pulse signal of the specified value NR. Sometimes the control unit 22
When configured so that the reverse drive of the motor 15 is terminated, the specified amount of syrup can be accurately delivered even after long-term use.

In the above embodiment, the rotation detection means was explained using the slit plate 20a and the photointerrupter 20b as an example, but this is explained by using a gear attached to the output shaft of the motor 15 and a gear attached to the outer periphery of the gear. A magnetic sensor supported from a fixed side so as to be located close to each other, and a permanent magnet for generating a bias magnetic field attached to the fixed side, and the magnetic flux of the permanent magnet interlinks with the magnetic sensor as the gear rotates. The same applies to a pulse generator that detects the rotation of the motor 15 based on a change in .

Effects of the Invention As described above, according to the configurations described in each claim, in a syrup pump 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 forward path to drive the diaphragm. Since the control unit drives the motor in normal rotation until the number of pulses reaches a predetermined number corresponding to the syrup amount, the amount of syrup discharged can be varied by simply changing the setting of the predetermined number of pulses in the control unit.

Furthermore, according to the second aspect of the invention, the control section is configured to drive in reverse until the return detection means detects the nut member, so that the nut member can be accurately returned to the true initial position, and the nut member can be returned to the true initial position for a long period of time. You can dispense the required amount of syrup.

[Brief explanation of the drawing]

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, 12...Transmission member, 15...Motor, 16...
- Screw shaft, 17... Nut member, 19... Micro switch [return detection means] N 20a, 20b... Slit plate, photo interrupter [rotation detection means], 22
...control section.

Claims (1)

[Claims] 1. In a syrup pump that transports syrup by reciprocating a diaphragm, a drive unit for reciprocating the diaphragm is screwed into a screw shaft rotationally driven by a motor, and the screw shaft is screwed to the screw shaft. a nut member slidable in the direction of the reciprocating movement of the diaphragm; a transmission member extending in the direction of the reciprocating movement of the diaphragm and having one end connected to the diaphragm and the other end connected to the nut member; A rotation detecting means outputs a pulse signal in accordance with the rotation, and the motor is driven in normal rotation until the pulse signal generated from the rotation detecting means coincides with a predetermined number of pulses corresponding to the required amount of syrup on the outward path to drive the diaphragm. A syrup pump consisting of a control section. 2. Return detection means for detecting that the nut member has returned to the initial position is provided, and the control unit is configured to drive the motor in reverse on the return path for driving the diaphragm until the return detection means detects the nut member. The syrup pump according to claim 1, wherein the syrup pump comprises: