JPH0124582Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automatic quantitative measuring machine for weighing fibrous raw materials with poor fluidity.

For example, as is well known, raw materials for friction materials for brakes have extremely poor fluidity, and tangled fibrous materials tend to harden when compressed. However, there is a problem that the amount flowing into the measuring container is not stable and the measuring accuracy is reduced. In order to avoid this, it has been proposed to install a loosening device at the discharge port of the screw feeder that transfers the raw material from the sump hopper to the measuring container (Japanese Utility Model Publication No. 18148/1983, No. 9475/1983). However, even with this proposal, compressed and hardened raw materials may not be sufficiently loosened during transfer by the screw feeder, and there are certain limits to improving weighing accuracy and shortening weighing time. It was hot.

The present invention was developed with the aim of addressing these problems and providing an automatic quantitative weighing machine that can improve weighing accuracy and shorten weighing time without compressing and solidifying raw materials. can be,
A quantitative feeder for controlling the supply of raw material to the screw feeder is disposed at the outlet of the reservoir hopper, and the amount of raw material supplied by this quantitative feeder is set to be smaller than the amount of raw material transferred by the screw feeder. Therefore, the raw material supplied from the sump hopper to the screw feeder is not compressed while being transferred by the screw feeder, and the loosening effect of the loosening device can be fully demonstrated, making it possible to The amount flowing into the container is stabilized, measurement accuracy is improved, and measurement time can be shortened.

Hereinafter, the present invention will be explained in detail with reference to an embodiment shown in the drawings.

1 is a schematic sectional view, and FIG. 2 is a partially cutaway schematic perspective view, in which 1 is a reservoir hopper, 2 is a screw feeder, 3 is a loosening device, 4 is a weighing machine, and 5
6 indicates a quantitative supply device and 6 indicates a raw material.

The screw feeder 2 has a large supply screw feeder 2a and a small supply screw feeder 2b mounted on parallel shafts inside a raw material transfer gutter 11, and each screw feeder 2a, 2b is driven by a variable speed motor 12a. , 12b. The loosening device 3 is provided at the discharge port 11a of the raw material transfer gutter 11, and is equipped with a crushing wheel 14 having blades 13 with serrated side edges, and corresponds to each screw feeder 2a, 2b. It consists of a large loosening device 3a and a small loosening device 3b. Crushing car 1 of each loosening device 3a, 3b
4 are driven by variable speed motors 15a and 15b, respectively. The weighing machine 4 includes a weighing container 4a, a discharge gate 4b, a load cell 4c, a support stand 4d, etc., and is arranged below the discharge port 11a. The weight of the raw material 6 that has flowed into the weighing container 4 is detected by a load cell 4c, amplified by an amplifier 19, input to a comparator 20, and compared with a preset weight value by a setting device 21. Control signals such as a forecast signal and a quantitative signal for the set value are output to the control circuit 22, and the control circuit 22 controls each motor. Note that the above configuration can be used as is as described in the above-mentioned publication.

Now, the quantitative feeding device 5 also includes a large quantitative feeding device 5a and a small quantitative feeding device 5b corresponding to each screw feeder 2a, 2b, and has the following configuration.

The large quantity supply device 5a is provided with rotary impellers 25, 25' having rotary shafts 25a, 25a'.
Gears 26, 26' are attached to the ends of the gears 26, 25a' and supported by a support 27, and a gear 28 meshing with the gears 26, 26' is attached to the end of the output shaft of the variable speed motor 30 and supported by a support 29. variable speed motor 30
It is now being driven by Therefore, as shown by arrows in FIG. 4, the rotary impeller 25 rotates clockwise and the rotary impeller 25' rotates counterclockwise.
On the other hand, the small quantity supply device 5b has a similar structure, and has a rotating impeller 3 having rotating shafts 31a and 31a'.
1 and 31' are provided, gears 32 and 32' are attached to the ends of the rotating shafts 31a and 31a', and a gear 34 that is supported by a support stand 33 and meshes with the gears 32 and 32' is attached to the output shaft end of the variable speed motor 36. As shown in FIG. 4, the rotary impeller 31 rotates clockwise and the rotary impeller 31' rotates counterclockwise. .

Each rotary impeller 25, 25', 31, 31' has blades 38 attached to positions that divide the outer periphery of a boss 37 fixed to the rotating shaft into eight equal parts, and the side edges of each blade 38 are serrated and made of fibers. It is designed to make it easier to scrape out the sexual raw material 6. In this embodiment, the length _l1 of the rotary impellers 25, 25' is 80 mm, and the rotation speed is approximately
10 rpm, the length l ₂ of the rotary impellers 31, 31' is
40 mm, and the rotation speed is approximately 2 rpm.The large quantity feeder 5a has a supply capacity about 10 times that of the small quantity feeder 5b, and the large quantity screw feeder 2
The raw material 6 is supplied in a fixed quantity to the small supply screw feeder 2b and the screw feeder 2b, and the transfer capacity of each screw feeder 2a and 2b is greater than the supply capacity of each fixed quantity feeder 5a and 5b. Set to
The raw material 6 is prevented from being compressed within the screw feeders 2a and 2b. The transfer capacity of each screw feeder 2a, 2b and each quantitative feeding device 5
The ratio of the supply capacities of a and 5b can be adjusted as appropriate by changing the speeds of the motors 30 and 36 according to the physical properties of the raw material 6, and is operated by setting it to twice or more, for example.

With the above configuration, the device is operated under the control of the control circuit 22. That is, control circuit 2
The quantitative feeder 5, the screw feeder 2, and the loosening device 3 are started at the same time by the measurement start signal of step 2.
The raw material 6 is quantitatively supplied to the screw feeder 2 by the quantitative supply device 5 provided at the outlet 1a of the reservoir hopper 1, and the raw material 6 transferred by the screw feeder 2 is loosened by the loosening device 3 and transferred to the weighing machine 4. is supplied to When the weight of the raw material 6 that has flowed into the weighing container 4a of the weighing machine 4 reaches the pre-quantitative setting value set in advance by the setting device 21, a forecast signal is output from the comparator 20, and the control circuit 22 controls the large quantity supply device 5a. Then, the large supply screw feeder 2a is stopped, and at the same time, the small quantity supply device 5b and the small supply screw feeder 2b are decelerated to perform a minute supply to the weighing machine 4. Next, when the weight of the raw material 6 in the weighing container 4a reaches the target setting value, a quantitative signal is output from the comparator 20, and the control circuit 22 controls the small amount feeding device 5b, the small feeding screw feeder 2b, and the loosening device 3a. ,3
b is stopped, the discharge gate 4b is opened, and the raw material 6 is discharged to the next process.

As is clear from the above explanation, according to the present invention, a quantitative feeder is arranged at the outlet of the sump hopper, and a quantity of raw material smaller than the transfer capacity of the screw feeder is supplied from the sump hopper to the screw feeder. This prevents the material from being compressed and hardened due to too much material being supplied to the screw feeder, and the loosening effect of the loosening device can be fully demonstrated to stabilize the amount flowing into the weighing machine. This makes it possible to improve weighing accuracy and shorten weighing time.

By the way, to give an example of the weighing results without and with a metering device, in the former case the weighing accuracy is ±
1g, the defect rate exceeding this range was 5 to 10%, and the limit of the weighing time was about 30 seconds for weighing 100g, but in the latter case, that is, in the embodiment of the present invention, the failure rate exceeded this range of ±0.75g. Accuracy has been significantly improved with a defective rate of less than 2%, and the time required to weigh 100g has been significantly shortened to approximately 20 seconds.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a schematic sectional view, FIG. 2 is a partially cutaway schematic perspective view, FIG. 3 is a sectional view of the main part, and FIG. It is a sectional view of the important part seen from the direction. 1...Tame hopper, 1a...Exit, 2, 2a,
2b... Screw feeder, 3, 3a, 3b...
... Loosening device, 4... Weighing machine, 4a... Measuring container, 4c... Load cell, 5, 5a, 5b... Constant supply device, 6... Raw material, 11a... Discharge port, 2
2...Control circuit.

Claims (1)

[Scope of Claim for Utility Model Registration] A screw feeder is arranged below the raw material hopper, a material loosening device is arranged at the discharge port of the screw feeder, a measuring container is arranged below the discharge port, In an automatic quantitative weighing machine that detects the weight of the raw material put into the weighing container and stops supplying the raw material to the weighing container when the weight reaches a set value, there is a screw feeder at the outlet of the sump hopper. An automatic quantitative weighing machine characterized by disposing a quantitative feeding device for controlling raw material supply, and setting the amount of raw material supplied by this quantitative feeding device to be smaller than the amount of raw material transferred by a screw feeder.