Quantitative feeding device

Abstract

To reduce costs in a quantitative supply device.SOLUTION: A cut gate 5 provided at a discharge port of a reservoir hopper 3 is driven by a stepping motor 10. In medium inputting, input control based on a setting time, which inputs an object to be weighed while reducing the opening of the cut gate 5 from a first setting opening to a second setting opening in the preset setting time, is performed, and even when an input weight of the object to be weighed that is input from the reservoir hopper 3 to a weighing hopper 4 and weighed contains a vibration component, the weighing can be carried out with high accuracy without being affected by the vibration component.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a constant-volume feeder that feeds a constant volume of an object to be weighed, and more particularly to a constant-volume feeder that is suitable for feeding a constant volume of powder or granular material. [Background technology]

[0002] As an example of a fixed quantity supply device, a cut gate of an automatic supply device is disclosed in Patent Document 1. In Patent Document 1, a cut gate (electric shutter) that can be opened and closed is provided at the outlet of a hopper that contains a large amount of objects to be weighed, a weighing bucket is placed below the outlet, and a predetermined amount of objects to be weighed is put into the weighing bucket by controlling the opening degree of the cut gate based on the weight of the objects to be weighed in the weighing bucket detected by a load cell, and a predetermined amount of objects to be weighed is supplied from the weighing bucket. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 62-18627 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned Patent Document 1, a servo mechanism is adopted in which the opening degree of the cut gate is detected by a position detector and a servo motor that drives the cut gate is feedback-controlled.

[0005] Such a servo mechanism has a problem in that its configuration is complicated and costly.

[0006] The present invention has been made in view of the above points, and has as its main object to reduce the cost of a constant volume supply device. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention is configured as follows.

[0008] (1) A quantitative supply device according to the present invention is a quantitative supply device comprising a storage hopper which stores objects to be weighed and discharges the objects from a discharge outlet at a lower portion thereof and feeds the objects into a weighing hopper, the weighing hopper which stores and weighs the objects fed from the storage hopper, and a control means which controls the amount of the objects to be weighed fed from the storage hopper into the weighing hopper, The weighing hopper is provided with a cut gate provided at the discharge outlet of the storage hopper and a stepping motor for driving the cut gate, and the control means controls the amount of the objects to be weighed that are discharged from the storage hopper to the weighing hopper by controlling the stepping motor to adjust the opening of the cut gate, and the control means switches between a first input stage in which the opening of the cut gate is maintained at a first set opening and the objects to be weighed are input until the input weight of the objects to be weighed that are input from the storage hopper to the weighing hopper becomes a first set weight, a second input stage in which the opening of the cut gate is reduced from the first set opening to a second set opening over a predetermined set time while controlling the input amount based on a set time, and the objects to be weighed are input while the opening of the cut gate is reduced from the first set opening to a second set opening over a predetermined set time, and a third input stage in which the opening of the cut gate is maintained at the second set opening and the objects to be weighed are input until the input weight of the objects to be weighed becomes a second set weight that is larger than the first set weight.

[0009] According to the quantitative supply device of the present invention, the cut gate provided at the discharge outlet of the storage hopper is driven by a stepping motor, thereby simplifying the configuration and reducing costs compared to conventional examples in which the cut gate is driven by a servo mechanism.

[0010] When the cut gate is driven by a stepping motor, which has a smaller output torque than a servo motor, when the opening of the cut gate is changed to feed the objects to be weighed into the weighing hopper, a wavy vibration component may be generated in the weight of the objects to be weighed that are fed into the weighing hopper and weighed due to the difference in the amount fed before and after the change.

[0011] According to the present invention, in the second feeding stage, which follows from the first feeding stage in which the objects to be weighed are fed at a relatively large first set opening, the opening of the cut gate is reduced from the first set opening to the second set opening over a pre-set time while the objects to be weighed are fed, and this is controlled based on a set time.This means that even if the weight of the objects to be weighed fed from the storage hopper to the weighing hopper contains vibration components, as in the case of controlling the opening of the cut gate based on the feed weight of the objects to be weighed fed from the storage hopper to the weighing hopper, it is not affected by this and highly accurate weighing is possible.

[0012] (2) In a preferred embodiment of the present invention, the control means drives the stepping motor in microsteps.

[0013] According to this embodiment, the stepping motor can be rotated at fine step angles by microstep driving, and vibration can be reduced to perform highly accurate measurement.

[0014] (3) In one embodiment of the present invention, in the second input stage, the control means is selectively able to switch, instead of the input amount control based on the set time, to input amount control based on input weight, in which the objects to be weighed are input while reducing the opening degree of the cut gate based on the input weight of the objects to be weighed to be input into the weighing hopper and weighed, and in the input amount control based on the input weight, the control means inputs the objects to be weighed while reducing the opening degree of the cut gate from the first set opening degree until the input weight of the objects to be weighed becomes a third set weight which is smaller than the second set weight.

[0015] According to this embodiment, in the second input stage, instead of input amount control based on a set time, it is possible to switch between input amount control based on input weight, in which the opening of the cut gate is reduced based on the input weight of the item to be weighed, and so it is possible to select either input amount control based on a set time or input amount control based on the input weight, depending on, for example, the properties of the item to be weighed, the magnitude of the set opening, etc.

[0016] (4) In a preferred embodiment of the present invention, in the control of the input amount based on the set time of the second input stage, the control means drives the stepping motor at a constant speed so that the opening of the cut gate changes from the first set opening to the second set opening during the set time.

[0017] According to this embodiment, by driving the stepping motor at a constant speed, the opening degree of the cut gate can be changed from the first set opening degree to the second set opening degree in a set time.

[0018] (5) In another embodiment of the present invention, the control means includes a setting display unit in which the set time, the first set weight, the second set weight, the first set opening, and the second set opening are set and the setting contents are displayed.

[0019] According to this embodiment, the settings required for switching between each input stage can be made by operating the setting display section.

[0020] (6) In yet another embodiment of the present invention, the setting display unit sets parameters of the stepping motor for reducing the opening of the cut gate from the first set opening to the second set opening in input amount control based on the set time of the second input stage, and displays the setting contents.

[0021] According to this embodiment, the stepping motor parameters required for adjusting the opening degree of the cut gate for input amount control based on the set time can be set by operating the setting display unit. Effect of the Invention

[0022] According to the present invention, the cut gate provided at the discharge outlet of the storage hopper is driven by a stepping motor, so that a fixed amount of the objects to be weighed can be supplied with a simple and inexpensive configuration without using a servo mechanism.

[0023] Furthermore, in the second feeding stage, the opening of the cut gate is reduced from the first set opening to the second set opening over a pre-set time while the objects to be weighed are fed in, and this is controlled based on a set time. This enables highly accurate weighing without being affected by vibration components contained in the weight of the objects to be weighed fed from the storage hopper to the weighing hopper, as is the case when the opening of the cut gate is controlled based on the weight of the objects to be weighed fed from the storage hopper to the weighing hopper. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a schematic diagram of a constant volume supply device according to one embodiment of the present invention. [Diagram 2] Figure 2 shows an example of the progression of large, medium and small inputs over time to explain the input amount control based on the set time, where Figure 2(a) shows the input weight of the object to be weighed in the weighing hopper, Figure 2(b) shows the opening degree of the cut gate, and Figure 2(c) shows the opening degree of the discharge gate. [Diagram 3] Figure 3 shows an example of the progression of large, medium and small inputs over time to explain input amount control based on input weight, where Figure 3(a) shows the input weight of the objects to be weighed in the weighing hopper, Figure 3(b) shows the opening degree of the cut gate, and Figure 3(c) shows the opening degree of the discharge gate. [Figure 4] FIG. 4 is a diagram showing the first setting display screen. [Diagram 5] FIG. 5 is a diagram showing the second setting display screen. [Figure 6] FIG. 6 is a flowchart illustrating the operation. [Figure 7]FIG. 7 is a flowchart illustrating the operation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0026] FIG. 1 is a schematic diagram of a constant volume supply device according to one embodiment of the present invention.

[0027] The constant-volume feeder 1 of this embodiment is suitable for feeding a predetermined weight of powdered or granular material such as resin pellets, polished rice, or animal feed.

[0028] This quantitative supply device 1 comprises a storage hopper 3 in which powdered or granular objects 2 to be weighed are stored, and a weighing hopper 4 disposed below the storage hopper 3 and into which the objects 2 to be weighed discharged from the storage hopper 3 are fed.

[0029] The objects 2 to be weighed are constantly dropped and fed into the rectangular cylindrical storage hopper 3 from a large storage hopper above (not shown) via a feed chute. A cut gate 5 is provided at the discharge outlet at the bottom of the storage hopper 3 so as to be rotatable forwards and backwards about a horizontal fulcrum 5a. By rotating this cut gate 5 to adjust the opening of the discharge outlet at the bottom of the storage hopper 3, the amount of the objects 2 to be discharged from the storage hopper 3 and fed into the weighing hopper 4 is controlled.

[0030] In this embodiment, in order to simplify the configuration and reduce costs compared to the conventional example using a servo mechanism, the cut gate 5 is rotationally driven by a cut gate stepping motor 10 via a link mechanism (not shown).

[0031] Figure 1 shows a state in which no objects to be weighed 2 have been put into the weighing hopper 4, i.e., the cut gate 5 is closed, and also shows, by imaginary lines, a state in which the cut gate 5 has rotated counterclockwise around the horizontal fulcrum 5a and the objects to be weighed 2 have been put into the weighing hopper 4.

[0032] The weighing hopper 4 is provided at its bottom with a pair of discharge gates 4a, 4b that are opened and closed simultaneously. When the pair of discharge gates 4a, 4b are closed, the weighing hopper 4 stores the objects to be weighed input from the storage hopper 3, and by opening the discharge gates 4a, 4b, a predetermined amount of the stored objects to be weighed 2 can be discharged downward. The discharge gates 4a, 4b are driven to open and close by a discharge gate stepping motor 11 via a link mechanism (not shown).

[0033] The weighing hopper 4 is equipped with a load cell 6 as a load sensor that measures the input weight, which is the weight of the objects to be weighed that are discharged from the storage hopper 3 and input into the weighing hopper 4. A load signal from this load cell 6 is input to a control unit 7 of control means 15. The control means 15 performs various settings such as a set time, a set weight, a set opening, or motor parameters, which will be described later, and is equipped with a setting display unit 8 that displays the settings. This setting display unit 8 is composed of, for example, a touch panel, and is connected to the control unit 7. The control unit 7 has a built-in timer function that measures a set time, etc.

[0034] The control unit 7 controls the amount of weighed objects 2 dispensed from the storage hopper 3 to the weighing hopper 4 by adjusting the opening degree of the cut gate 5 which is rotated by the stepping motor 10 by controlling the stepping motor 10 for the cut gate via the first driver 9.

[0035] The larger the opening of the cut gate 5, the larger the amount of the objects 2 fed into the weighing hopper 4, and the smaller the opening of the cut gate 5, the smaller the amount of the objects 2 fed into the weighing hopper 4. When the cut gate 5 is closed, the feeding of the objects 2 from the storage hopper 3 to the weighing hopper 4 is stopped.

[0036] The control unit 7 controls the discharge gate stepping motor 11 via the second driver 12 to control the opening and closing of the discharge gates 4a, 4b of the weighing hopper 4. When the weight of the objects 2 to be weighed fed into the weighing hopper 4 reaches a predetermined amount, the control unit 7 opens the discharge gates 4a, 4b to discharge the predetermined amount of the objects 2 to be weighed.

[0037] In this embodiment, the control unit 7 controls the amount of the objects 2 to be weighed fed from the reservoir hopper 3 to the weighing hopper 4 by switching between three main stages.

[0038] In other words, when the objects to be weighed 2 start to be fed from the storage hopper 3 to the weighing hopper 4, the feeding is switched between three stages: a large feeding stage in which the opening of the cut gate 5 is set to a relatively large opening and a large amount of the objects to be weighed 2 is fed into the weighing hopper 4; a medium feeding stage in which the opening of the cut gate 5 is reduced and the objects to be weighed 2 are fed into the weighing hopper 4 in a medium amount; and a small feeding stage in which the opening of the cut gate 5 is kept small during the medium feeding stage and the objects to be weighed 2 are fed into the weighing hopper 4 in a small amount.

[0039] In this embodiment, as described above, in order to simplify the configuration and reduce costs, the cut gate 5 is driven by the cut gate stepping motor 10 without using a servo mechanism.

[0040] However, in the case of a stepping motor, which has a smaller output torque and a coarse step angle compared to a servo motor, when the opening of the cut gate 5 is switched to feed the objects 2 to be weighed into the weighing hopper 4, a wavy vibration component may be generated in the weight of the objects to be weighed that are fed into the weighing hopper 4 and weighed due to the difference in the amount fed before and after the switch and the properties of the objects to be weighed.

[0041] For this reason, in this embodiment, even if the weight of the objects to be weighed that are put into the weighing hopper 4 contains vibration components, the weighing can be performed with high accuracy without being affected by the vibration components. The following configuration is adopted.

[0042] In other words, in the medium charge following a large charge in which a large amount of the objects to be weighed 2 are charged into the weighing hopper 4, the amount of the objects to be weighed 2 charged from the storage hopper 3 to the weighing hopper 4 can be controlled based on a set time.

[0043] This input amount control based on a set time is a control in which the objects to be weighed 2 are input into the weighing hopper 4 while reducing the opening degree of the cut gate 5 from a first set opening degree to a second set opening degree over a preset set time.

[0044] Figure 2 shows an example of the progression of large input (large throw), medium input (medium throw) and small input (small throw) over time to explain the input amount control based on this set time, where Figure 2(a) shows the input weight Wx, which is the measured weight of the object 2 to be weighed in the weighing hopper 4, Figure 2(b) shows the opening degree of the cut gate 5, and Figure 2(c) shows the opening degree of the discharge gates 4a and 4b.

[0045] In this embodiment, as shown in FIG. 2(b), the cut gate 5 starts to open from time t0 and is maintained at a first set opening AP1, which is a preset opening for large input (large input opening), and the objects to be weighed 2 are input from the storage hopper 3 to the weighing hopper 4, so that the input weight Wx of the objects to be weighed 2 to be weighed in the weighing hopper 4 increases, as shown in FIG. 2(a).

[0046] This first set opening AP1 is set to a relatively large value, and in the large-scale pouring mode, the objects 2 to be weighed are poured from the reservoir hopper 3 into the weighing hopper 4 in a relatively large amount.

[0047] When the weight Wx of the objects to be weighed 2 fed into the weighing hopper 4 by this large feed reaches a first set weight W1, which is a pre-set large feed amount, as shown in Figure 2(a), at that point in time t1, the large feed is switched to a medium feed.

[0048] In this medium input, the input amount control based on the set time is performed. In the input amount control based on the set time, the opening degree of the cut gate 5 is reduced from the above-mentioned first set opening degree (large throw opening degree) AP1 to a second set opening degree AP2, which is a preset opening degree for small input (small throw opening degree), at a set time T1, as shown in Fig. 2(b). At this time, the cut gate stepping motor 10 is driven at a constant speed.

[0049] The constant speed of this cut gate stepping motor 10 is calculated from the first set opening AP1 for large input, the second set opening AP2 for small input, and the set time T1 for medium input, which are pre-set by the setting display unit 8, as described below.

[0050] In this input amount control based on the set time, at time t1, medium input is started at the first set opening AP1 for large input, and at time t2, when the set time T1 for medium input has elapsed, the opening of the cut gate 5 becomes the second set opening AP2 for small input. As a result, in medium input, as the opening of the cut gate 5 decreases over time, the rate of increase in the input weight Wx of the objects 2 to be weighed also decreases, as shown in FIG. 2(a).

[0051] Then, when the set time T1 for medium input has elapsed and the opening angle of the cut gate 5 reaches the second set opening angle AP2, which is the opening angle for small input, at that point t2, the input switches from medium input to small input, and during small input, the opening angle of the cut gate 5 is maintained at the second set opening angle AP2 as shown in Figure 2(b).

[0052] Accordingly, the amount of the objects 2 put in becomes a relatively small constant value according to the second set opening AP2, and the rate of increase in the put-in weight Wx further decreases, as shown in FIG. 2(a).

[0053] Even after the cut gate 5 is closed, the input weight Wx continues to increase by the drop amount Wd corresponding to the drop from the storage hopper 3 to the weighing hopper 4.

[0054] Therefore, in the case of small loading, as shown in Figure 2(a), when the loading weight Wx reaches the second set weight W2 (=Wp-Wd), which is the weight obtained by subtracting the drop difference Wd from the predetermined target weight Wp, at that point t3, the opening of the cut gate 5 is reduced and closed to stop the loading of the object to be weighed 2.

[0055] Finally, as shown in Fig. 2(a), at time t4 when the stabilization time T2 measured by the stabilization timer has elapsed, the input weight Wx converges to a value close to the predetermined amount Wp, which is the target weight value. When this predetermined amount Wp is obtained, the discharge gates 4a and 4b of the weighing hopper 4 are opened and closed for the discharge time T3 measured by the discharge timer, as shown in Fig. 2(c), and the predetermined amount of the objects 2 to be weighed supplied to the weighing hopper 4 is discharged from the weighing hopper 4. This completes one fixed-quantity supply.

[0056] As described above, in the medium feeding mode, the amount of the objects 2 to be weighed fed from the storage hopper 3 to the weighing hopper 4 is controlled based on a set time without using the feeding weight Wx of the objects 2 to be weighed fed into the weighing hopper 4 and weighed. Therefore, even if a vibration component occurs in the feeding weight Wx of the objects 2 to be weighed fed into the weighing hopper 4 and weighed due to the difference in the feeding amount before and after the opening of the cut gate 5 is changed or the properties of the objects to be weighed, it is possible to perform highly accurate weighing without being affected by this.

[0057] Furthermore, in this embodiment, the control means 15 drives the cut gate stepping motor 10 in micro steps so that the cut gate stepping motor 10 can be rotated at fine step angles. It is preferable to make the basic step angle finer, about 1 / 4 to 1 / 8, and in this embodiment, for example, one step of 1.8° is rotated at 1 / 8 of that, that is, 0.225°. By driving the cut gate stepping motor 10 in this manner in micro steps, vibrations can be reduced and measurement can be performed with even higher accuracy.

[0058] In cases where a vibration component occurs in the input weight Wx of the objects to be weighed that are input into the weighing hopper 4 and weighed, the input amount control based on the above-mentioned set time allows for appropriate control without being affected by the vibration component of the input weight Wx. However, for example, depending on the properties of the objects to be weighed and the magnitude of the set opening, it may be preferable to perform input amount control based on the input weight Wx rather than input amount control based on the set time, in which case no vibration component will occur in the input weight Wx.

[0059] Therefore, in the medium feeding of this embodiment, instead of the feeding amount control based on the set time described above, it is possible to select a feeding amount control based on the feeding weight Wx of the objects to be weighed while reducing the opening degree of the cut gate 5 and feeding the objects 2. This switching selection can be made by a setting operation of the setting display unit 8.

[0060] This control based on the input weight Wx is a control in which the objects to be weighed 2 are input into the weighing hopper 4 while reducing the opening of the cut gate 5 based on the input weight Wx, which is the measured weight of the objects to be weighed 2 input from the storage hopper 3 to the weighing hopper 4 and weighed in the weighing hopper 4.

[0061] Figure 3 shows an example of the progression over time of large input (large throw), medium input (medium throw) and small input (small throw) to explain the input amount control based on this input weight Wx, where Figure 3(a) shows the input weight Wx, which is the measured weight of the object 2 to be weighed measured by the weighing hopper 4, Figure 3(b) shows the opening degree of the cut gate 5, and Figure 3(c) shows the opening degree of the discharge gates 4a and 4b.

[0062] Since the process after large and small input is the same as that shown in FIG. 2, the medium input, which controls the input amount based on the input weight Wx, will be explained.

[0063] When the input weight Wx of the objects 2 to be weighed that have been input into the weighing hopper 3 by large input and weighed reaches a first set weight W1, as shown in FIG. 3(a), at time t1, the input is switched from large input to medium input.

[0064] In this intermediate feed, the opening degree AP of the cut gate 5 is reduced as the feed weight Wx measured by the weighing hopper 4 increases. Specifically, the opening degree AP of the cut gate 5 is controlled to the opening degree calculated based on the following equation (1).

[0065] [Equation (1)] In this equation (1), W3 is a preset third set weight, and this third set weight W3 is larger than the above-mentioned first set weight W1 and smaller than the above-mentioned second set weight W2 (= Wp - Wd) for stopping the feed of small feed (W1 < W3 < W2). Also, the power exponent α is an arbitrary value satisfying 0.3 ≤ α ≤ 0.7, and in this embodiment, α = 0.5. Note that AP1 and AP2 are the first set opening degree AP1 for large feed and the second set opening degree AP2 for small feed described above.

[0066] In the intermediate feed for performing the feed amount control based on this feed weight Wx, as the opening degree AP of the cut gate 5 decreases according to the above equation (1) with the passage of time t, the feed amount of the material to be weighed 2 is gradually reduced, so the increase rate of the feed weight Wx also gradually decreases.

[0067] And when the feed weight Wx reaches the third set weight W3 (Wx = W3), at that time point t2, it switches from intermediate feed to small feed.

[0068] Note that the opening degree AP of the cut gate at the time point t2 when switching from this intermediate feed to small feed becomes the second set opening degree AP2 as can be seen from the above equation (1). Thereafter, it is the same as in FIG. 2 above.

[0069] Next, the setting operations necessary for performing the above-mentioned large feed, intermediate feed, and small feed controls will be described.

[0070] FIG. 4 is a diagram showing a first setting display screen which is an example of a setting display screen by the setting display unit 8, and FIG. 5 is a diagram showing a second setting display screen.

[0071] As shown in Figure 4, the above-mentioned predetermined amount Wp, which is the target weight of the objects 2 to be weighed discharged from the weighing hopper 4, the upper weight limit, the lower weight limit, the above-mentioned stability timer time, the discharge timer time, and the waiting time after discharge are set.

[0072] Also, as shown in Figure 5, in control based on the input weight Wx, a predetermined amount, which is the third set weight W3 at which medium input is switched to small input, a large input amount, which is the first set weight W1 at which large input is switched to medium input, a drop amount Wd required to calculate the second set weight W2 (=Wp-Wd) which is the weight at which small input is stopped, a large input opening, which is the first set opening AP1, a small input opening, which is the second set opening AP2, input amount control based on set time or input amount control based on input weight is switched and a medium input time, which is the set time T1, is set when input amount control based on set time is selected.

[0073] When the mid-throw time is set to "0.00", input amount control based on the input weight is selected, and when a value other than "0.00" is set, input amount control based on the set time is selected and the mid-throw time (set time T1) is set to the set value.

[0074] As shown in FIG. 5, in order to control the driving of the cut gate stepping motor 10, motor parameters such as the motor start speed, end speed, motor maximum speed, motor acceleration, and motor deceleration offset are set for large input and small input.

[0075] Here, the calculation of the speed of the cut gate stepping motor 10 in the input amount control based on the above-mentioned set time will be described.

[0076] In this input amount control based on the set time, the required speed of the cut gate stepping motor 10 is calculated from the first set opening AP1, which is the large throw opening, the second set opening AP2, which is the small throw opening, and the medium throw time, which is the set time T1.

[0077] The speed V (Hz) of the cut gate stepping motor 10 is calculated by the following formula, assuming that the pulse numbers A and B of the first set opening AP1 and the second set opening AP2 are set to a medium opening set time T1.

[0078] V=(AB) / T1 For example, in the example in Figure 5, one rotation is 360° and normally one step is 1.8°, but as described above, by using microstep driving, one step is divided into 1 / 8, so the number of motor drive pulses per rotation is 1600pls (=360*8 / 1.8).

[0079] If the full opening degree of the cut gate 5 is set to, for example, 50%, the number of pulses when the cut gate 5 is fully opened is 800 pls.

[0080] If the first set opening AP1, which is the large opening, is set to, for example, 29% as shown in FIG. 5, the number of pulses A of the first set opening AP1 is as follows: A=800×029=232 In addition, if the second set opening AP2, which is the small throw opening, is set to, for example, 14% as shown in FIG. The number of pulses B for the second set opening AP2 is: B=800×0.14=112 It becomes.

[0081] If the set time T1, which is the intermediate throw time, is set to, for example, 0.5 sec, the motor speed V of the cut gate stepping motor 10 is The motor speed V is (232-112) / 0.5=240 (Hz), and the drive settings of the cut gate stepping motor 10 are as follows:

[0082] Motor start and end speed 240(Hz) Maximum motor speed: 240(Hz) Motor acceleration 0(Hz) Motor deceleration offset 0step By driving the cut gate stepping motor 10 at this calculated speed, the opening degree of the cut gate 5 is reduced from the first set opening degree AP1 to the second set opening degree AP2 in the set time T1.

[0083] 6 and 7 are flow charts illustrating the operation of the above embodiment.

[0084] First, in FIG. 6, the input is started (step S1), and the input sequence process of FIG. 7 described later is started (step S2), and it is determined whether or not there is a sequence reset request such as an emergency stop (step S3). If there is no sequence reset request, it is determined whether or not an alarm is generated due to the input weight exceeding the upper weight limit, for example (step S4). If there is no alarm, it is determined whether or not the sequence is completed (step S5). If there is no sequence reset request in step S3, and if there is no alarm in step S4, it is transitioned to a 10 ms sleep (step S6). If there is no sequence reset request in step S3, and if there is no alarm in step S4, it is transitioned to a sequence reset process (step S7), and further transitioned to step S6. If there is no sequence completion in step S5, it is determined whether or not there is a step progress (step S8). If there is a step progress, it returns to step S2, and if there is no step progress, it transitions to a 10 ms sleep (step S9).

[0085] In the input sequence process, as shown in FIG. 7, it is determined whether input has started or whether the input amount has reached a target (step S10). It is determined whether a large input, a medium input, a small input, or the input is complete.

[0086] When input starts or input amount reaches a target, the parameters are rewritten to parameters corresponding to the next input (step S15). Specifically, the motor parameters such as the input opening, start and end speeds, maximum speed, acceleration, deceleration offset, etc. are rewritten to parameters corresponding to the next input.

[0087] In the above step S10, if the injection has not started and the injection amount has not reached the target, it is determined whether or not medium injection is in progress (step S11), and if medium injection is not in progress, it is determined that large injection or small injection is in progress and the current opening degree is maintained (step S16).

[0088] If medium insertion is selected in step S11, it is determined whether or not a medium insertion time has been set (step S12). If the medium insertion time has not been set, the opening degree is updated to an opening degree corresponding to the insertion weight (step S13). If the medium insertion time has been set, the opening degree is updated to a value based on the insertion time (step S14).

[0089] As described above, according to this embodiment, the cut gate 5 provided at the discharge outlet of the storage hopper 3 is driven by the cut gate stepping motor 10, so that a fixed amount of the object to be weighed can be supplied with a simple and inexpensive configuration without using a servo mechanism.

[0090] Furthermore, in the medium feeding mode, the opening of the cut gate 5 is reduced from the first set opening AP1 to the second set opening AP2 over a preset time while the objects to be weighed are fed in, and this control of the feeding amount is based on a set time. Therefore, even if the weight of the objects to be weighed fed from the storage hopper 3 to the weighing hopper 4 contains vibration components, as in the case of controlling the opening of the cut gate 5 based on the feeding weight of the objects to be weighed fed from the storage hopper 3 to the weighing hopper 4, it is not affected and highly accurate weighing is possible.

[0091] In the above embodiment, the discharge gates 4a and 4b of the weighing hopper 4 are opened and closed by a stepping motor, but may be opened and closed by an air cylinder or the like. [Explanation of symbols]

[0092] 1 Quantitative feeding device 3 Storage hopper 4 Weighing hopper 5 Cut Gate 6 Load Cells 7 Control section 8 Setting display area 10 Cut gate stepping motor 15 Control Means

Claims

1. A quantitative supply device comprising: a storage hopper for storing objects to be weighed and discharging the objects from a discharge port at a lower portion thereof and feeding the objects into a weighing hopper; the weighing hopper for storing and weighing the objects fed from the storage hopper; and a control means for controlling an amount of the objects to be weighed fed from the storage hopper into the weighing hopper, A cut gate is provided at the discharge port of the storage hopper, and a stepping motor is provided to drive the cut gate. the control means controls the stepping motor to adjust the opening degree of the cut gate, thereby controlling the amount of the objects to be weighed that is fed from the storage hopper to the weighing hopper; the control means switches between a first input stage in which the opening of the cut gate is maintained at a first set opening and the objects to be weighed are input from the storage hopper to the weighing hopper until the input weight of the objects to be weighed reaches a first set weight, a second input stage in which the opening of the cut gate is reduced from the first set opening to a second set opening over a preset time period while controlling the input amount based on a set time, and a third input stage in which the opening of the cut gate is maintained at the second set opening and the objects to be weighed are input until the input weight of the objects to be weighed reaches a second set weight that is larger than the first set weight. A quantitative supply device characterized by:

2. The control means drives the stepping motor in micro steps. The constant rate supply device according to claim 1.

3. the control means is capable of selectively switching, in the second feeding stage, to feeding amount control based on a feeding weight, in which the objects to be weighed are fed into the weighing hopper while reducing the opening degree of the cut gate, based on the feeding weight of the objects to be weighed, instead of the feeding amount control based on the set time, In the input amount control based on the input weight, the control means inputs the objects to be weighed while decreasing the opening degree of the cut gate from the first set opening degree until the input weight of the objects to be weighed becomes a third set weight which is smaller than the second set weight.

3. The constant volume supply device according to claim 1 or 2.

4. In the control of the input amount based on the set time in the second input stage, the control means drives the stepping motor at a constant speed so that the opening degree of the cut gate changes from the first set opening degree to a second set opening degree within the set time.

4. The constant volume supply device according to claim 1.

5. the control means includes a setting display unit on which the set time, the first set weight, the second set weight, the first set opening degree, and the second set opening degree are set and the set contents are displayed, 5. A constant volume supply device according to claim 1.

6. The setting display unit sets parameters of the stepping motor for reducing the opening degree of the cut gate from the first set opening degree to the second set opening degree in the input amount control based on the set time of the second input stage, and displays the setting contents. The constant rate supply device according to claim 5.

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