JP2582371B2 - Electromagnetic vibration feeder for combination weighers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention is used to efficiently combine objects to be weighed such as frozen foods, uncooked foods and raw vegetables into a fixed amount with a variation in weight. And a dispersing and feeding device for a combination weigher.

(Prior Art) Japanese Utility Model Application Laid-Open No. 58-1015 shows an example of an electromagnetic vibration feeder of one unit, and Japanese Patent Application Laid-Open No. 60-153335 discloses a combination weigher using a plurality of such feeders as distribution feeders. 1
Here is an example.

In a combination weigher that handles raw foods at a manufacturing plant for sausage, ham, etc., it is necessary to frequently wash the weigher because oil, sticky substances, scum, and the like adhere to troughs and the like. If necessary, sterilize with steam. Therefore, waterproof and dustproof properties are required for electrical components such as vibrators.

In the field of handling frozen foods, the temperature of the surrounding environment of the scale changes in the range of −10 ° C. to 10 ° C. while the scale is operating or stopped.
Therefore, if water that has been washed remains during the stoppage, it will freeze during operation.

Japanese Utility Model Application Laid-Open No. 58-1015 is an example in which an electromagnet portion of an electromagnetic vibration feeder is covered with a case to form a waterproof and dustproof hermetic structure. However, the part of the vibrating leaf spring cannot be hermetically sealed, and when multiple leaf springs are used, water enters the gaps between the leaf springs and becomes unsanitary. As a result, the characteristics as described above are remarkably deteriorated.

Japanese Utility Model Publication No. 347442 shows a structure that closes both the electromagnet and the leaf spring of the electromagnetic vibrator, but this structure requires a large space behind the lower part of the transport trough, and this part has dimensional restrictions. Is a major design obstacle.

FIG. 9 shows a basic structure of a typical example of a conventional electromagnetic vibration feeder having a waterproof structure, and a pair of diaphragm springs (3) extending obliquely upward from a main body (2) supported on a floor by a mount spring (1). And (3) an electromagnet (5) that supports the transport trough (4) substantially horizontally through (3) and is provided between the main body and the leaf spring.
Vibration for conveying articles on the trough is added to the conveying trough by the suction piece (6), and the electromagnet and the leaf spring are covered with a waterproof / dustproof cover (7) and a sealing bellows (8).

(Problems to be Solved by the Invention) With the electromagnetic vibration feeder of the prior art shown in FIG. 9, waterproof and dustproof properties can be obtained, but the trough (4) is inevitably provided by providing the cover (7) and the bellows (8). The vertical distance between the body and the main body (2) increases. As a result, the position of the center of gravity (G ₁ ) of the transport trough (4) increases, and the line (y) connecting the center of gravity (G ₁ ) and the center of gravity (G ₂ ) of the main body approaches vertically. The overall center of gravity (G ₀ ) of the transport trough and the body lies on this line (y).

The direction in which the transport trough (4) supported by the leaf springs (3) and (3), which is generated by the electromagnet (5) attracting the attraction piece (6), tends to be displaced is substantially the leaf spring (3).
(3), and the angle (θ) formed by the vibration displacement direction of the transport trough and the line (y) becomes large. Therefore, a line (x ₁ ) passing through the center of gravity (G ₁ ) of the transport trough and a line (x ₂ ) passing through the center of gravity (G ₁ ) of the transport trough are separated upward from the line (x ₁ ) passing through the entire center of gravity (G ₀ ) in the vibration displacement direction of the transport trough. , The distance (h) therebetween becomes large.

Due to this geometric relationship, the moment Fh, which is the product of the trough vibration force F and the distance h, becomes large.

In a vibration feeder in which the main body (2) is supported in a floating state by the mount spring (1), a swinging motion as indicated by arrows (M) and (M ') around the center of gravity (G ₀ ) is caused by this moment. This causes the conveyed articles to jump and prevent normal conveyance, resulting in a decrease in performance.

(Means for Solving the Problems) The present invention has been made to solve the problems of the prior art, and as described above, a vibration feeder having a large swing moment is connected to a vibration feeder via a mounting leaf spring from its main body. A swing prevention weight is attached to cancel the swing moment.

That is, the electromagnetic vibration feeder for a combination weigher or the like of the present invention has an overall configuration based on a main body supported in a floated state from the floor via a mount spring, and a pair of front and rear vibrating leaf springs extending diagonally upward therefrom. The transport trough is supported substantially horizontally, and vibrations for transporting articles on the trough are added to the transport trough by an excitation electromagnet provided between the main body, a leaf spring, and the trough. When each line passing through the center of gravity of the entire vibrator is viewed parallel to the direction of vibration displacement of the transport trough, if the line passing through the center of gravity of the transport trough is separated upward, swinging is prevented from the main body via the mounting leaf spring. Attach weight,
An electromagnetic vibration feeder is provided in which the vibration of the transport trough and the vibration of the swing prevention weight resonate in opposite phases.

FIG. 1 shows the basic structure of a unit electromagnetic vibration feeder according to the present invention in comparison with the prior art shown in FIG. The feeder is mounted on a floating body via a mounting spring distributed on the floor.
The transport trough (4) is supported substantially horizontally on a pair of front and rear vibrating leaf springs (3) (3) extending obliquely upward from the base of the main body (2). A vibration for transporting the articles on the trough is added to the transport trough by an exciter including an electromagnet (5) and a suction piece (6) equipped on the transport trough, and a swing prevention weight (9) is attached to the mounting plate. It is attached to the main body (2) via a spring (10). Main body (2) including swing prevention weights (9), diaphragm springs (3) (3), exciters (5) (6)
Since the whole of the system consisting of is covered with the waterproof / dustproof cover (7) and the sealing bellows (8), the center of gravity of the transport trough (4) is necessarily higher than the center of gravity of the entire vibrator.

(Operation) In the electromagnetic vibration feeder of the present invention shown in FIG. 1, a current obtained by half-wave rectifying an alternating current of a commercial frequency as shown in FIG. I do.
The electromagnet draws the suction piece (6) by the electromagnetic force, and at the same time, the diaphragm springs (3) and (3) bend. When the current is cut off, the leaf spring returns. By this repetition, the transport trough (4) vibrates in a direction substantially perpendicular to the leaf spring. In order to improve the efficiency, it is usual that the natural frequency of the vibration system including the transport trough is selected near the power supply frequency, and the frequency of the transport trough resonates with the frequency of the excitation system.

As a result, as shown in FIG. 3, the articles on the transport trough (4) move away from the trough only when the trough is pulled down obliquely, because the descending speed of the trough is very fast. When it falls naturally and then starts to return diagonally upward, it contacts the trough in the initial stage and is carried on the trough as it is, moving upward and forward, receiving acceleration in the upward and forward direction. The article leaves the trough and is thrown upward and forward, and falls naturally by gravity. In this way, the article that has been subjected to the oblique vertical vibration from the trough will move forward while pulsating. It is appropriate that the trough vibrates at an angle of 20 to 25 ° to the horizontal.
Below ゜, the separation of the articles from the trough is poor, and above 25 ら れ, they are too much lifted upward, resulting in poor transport efficiency.

In the prior art transport feeder shown in FIG. 9, the occurrence and increase of the oscillating motions (M) and (M ') make it difficult to carry out such article transport smoothly. The transportation of the article proceeds smoothly. Also, by reducing the swinging motion, the adverse effect on the balance is reduced.

FIG. 4 is for analyzing a simplified dynamic model of the operation principle of the oscillating motion in the transport feeder of the present invention, and each mass and spring force are indicated by the following symbols.

Transfer trough (4) mass m ₁ Swing prevention weight (9) mass m ₂ Oscillating leaf spring (3) (3) Spring constant k ₁ Leaf spring (10) (10) Spring constant k ₂ for mounting anti-swing weight (2) Mass m ₃ Mount spring (1) Spring constant k _{3 In} the model shown in FIG. 4, the mass m ₁ of the transport trough, the natural frequency of the vibration system formed by the diaphragm spring k _1, and the When the mass m ₂ and the natural frequency of the vibration system formed by the mounting leaf spring k ₂ are made equal, when the center of gravity m ₁ of the transport trough is vibrated to m ₁ ′, the swing prevention weight m ₂ becomes
Displace to the position of m ₂ ′. The "m ₂ when vibration displacement in the m _2" m ₁ is m ₁ is displaced to the position of the. That vibrate mutually in opposite phase with m ₁ and m _2, the pitching motion and the vibration displacement of the body mass m ₃ is reduced moment generated by the m ₁ and m ₂ are cancel each other out each other. Improved as a result, prevents rocking pitching motion caused by the entire system comprising a body m ₃ is bent mount spring k _3, a direction conveying trough (4) is swung, that is, the direction of the efficiency for transporting the articles Can be done.

Strictly speaking, as shown in the model of FIG. 4, two leaf springs (10) and (10) for mounting the swing prevention weight are arranged in parallel and are the same as the vibrating leaf springs (3) and (3). it is necessary to make the movement of the rocking motion preventing weight m ₂ and positioned at an angle on the same parallel motion and movement of the conveyor trough m _1, practically the rocking motion preventing weight mounting plate spring as in the first view ( 10) may be one, and the angle may be slightly different from that of the diaphragm spring (3).

As a result, when the present invention has a practical design, the space behind the transport feeder is small and the center of gravity of the transport trough is high,
It is particularly advantageous.

(Embodiment) FIGS. 5, 6 and 7 show an embodiment in which a plurality of unit electromagnetic vibration feeders are arranged in a circular row to constitute a combination weigher.

In this embodiment, the transport troughs (4A) are arranged adjacent to each other in the circumferential direction, with the article transport direction as the radial direction.

In particular, in this embodiment, an inclined plate (11) is mounted on each of the swing prevention weights (9A) of the unit electromagnetic vibration feeder, and these inclined plates (11) come close to the center of the transport trough (4A) group together. The overlap is arranged so as to conform to the rotating conical surface as a whole. Then, as shown in FIG. 7, the adjacent inclined plates (11) can be freely oscillated independently of each other by nesting as shown in FIG. 7 so that the clearance (12) is maintained. In some cases, it is prevented from entering through this gap. On the open portion at the center of the group of inclined plates (11), a small cap-shaped cap (13) is attached to the upper end of a column (14) erected from the floor so as to closely overlap with each other. The protruding part of the swing prevention weight (9A) connected to the inclined plate (11) is surrounded by a sealing bellows (15) so that waterproof and dustproof properties are not lost. In order to prevent intrusion of particles, the upper surface of the inclined plate (11) may be covered with a thin flexible material cover (16) as shown in FIG.

In the embodiment of the present invention constructed in this combination weigher, a large-sized dispersion feeder provided at the center of the transport trough group shown in FIG. The electromagnetic vibrator is not required. Then, in this embodiment, the attached inclined plate (11) is vibrated by using a vibrating swing prevention weight (9A), and the inclined plate (11) is vibrated.
Can be provided with an article supply function of sending out the articles supplied to the transport trough (4A) ahead.

Since the transport trough (4A) and the inclined plate (11) of each electromagnetic vibration feeder vibrate independently of the adjacent feeder, when the transport trough in front of the individual inclined plate is in the vibration transport state, At the same time, the inclined plate is in the vibration supply state, so that the useless useless article is not pushed and supplied to the conveyance trough which is not in the vibration conveyance state as shown in FIG. 1 of Japanese Patent Application Laid-Open No. 60-153335. In this way, it is possible to perform rational distribution of articles to each transport trough and supply and transport of articles to be connected smoothly.

(Effects of the Invention) As described above, according to the present invention, the swing prevention weight is attached to the electromagnetic vibration feeder via the leaf spring, and the vibrations of the transport trough and the swing prevention weight are caused to vibrate in opposite phases. Since the swinging motion of the main body base can be substantially suppressed, even if the transport trough is at a high position, it is possible to efficiently transport the articles. In addition, since the swinging motion of the main body base does not adversely affect the weighing system, the weighing accuracy is improved.
Since the transport trough can be installed at a high position, a structure having a higher waterproof and dustproof function than before can be easily realized. In addition, by attaching an inclined plate to the swing prevention weight part, the inclined plates are arranged adjacent to each other in the radial direction,
In the combination weigher, the articles supplied to the center can be smoothly and continuously distributed to the respective transport troughs efficiently without newly providing a dispersion feeder at the center. In addition, since the structure is simple, the production cost can be reduced and an inexpensive combination weigher can be supplied.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing a basic structure of one unit of an electromagnetic vibration feeder according to the present invention, FIG. 2 is a diagram showing a waveform of a power supply current applied to the electromagnet, and FIG. FIG. 4 is a side view showing the movement of an article, FIG. 4 is a mechanical model diagram showing the principle of operation of preventing an oscillating motion in the electromagnetic vibration feeder of the present invention, and FIG. 6 is a partial plan view thereof, FIG. 7 is a cross-sectional view taken along line VII of FIG. 5 showing a state in which the inclined plate faces each other, FIG. 8 is a vertical sectional side view of a modification of the present invention, and FIG. It is a vertical side view which shows the basic structure of the typical example of the electromagnetic vibration feeder of the waterproof structure of FIG. (1) Mount spring (2) Body (3)
Vibrating plate spring, (4) (4A)… Transport trough, (5)…
Excitation electromagnet, (6) Suction piece, (7) Waterproof and dustproof cover, (8) (15) Sealed bellows, (9) (9A)
…… Swing prevention weight, (10) …… Installation leaf spring, (1
1) Inclined plate, (12) Clearance gap, (13) Cap, (14) Support, (16) Cover, (y)
(X ₁ ) (x ₂ ): characteristic line, (θ): angle, (h):
Distance, (G ₁ ) (G ₂ ) (G ₀ ) ... center of gravity, (F)… oscillation force, (M) (M ′)… oscillating motion, (m ₁ ) (m ₁ ′)
(M ₁ ″) center of mass, (m ₂ ) (m ₂ ′) (m ₂ ″) center of mass, (m ₃ ) mass, (k ₁ ) (k ₂ ) (k ₃ ) ... Spring constant.

Claims (3)

(57) [Claims] The present invention relates to a vibration trough spring which extends obliquely upward from a main body which is mounted on a floor via a mounting spring via a mounting spring, and a transfer trough is supported substantially horizontally, and an excitation provided between the main body, the leaf spring and the trough. In a vibration feeder having a structure in which vibration for transporting an article on a trough is added to a transport trough by an electromagnet, the center of gravity of the transport trough and the center of gravity of the entire vibrator in a direction parallel to the vibration displacement direction of the transport trough. When each passing line is separated in a direction perpendicular to the vibration displacement direction of the transport trough, a swing prevention weight that vibrates along with the vibration of the main body is attached from the main body via a mounting leaf spring, and An electromagnetic vibration feeder for a combination weigher or the like, characterized in that the vibration of the vibration preventing weight and the vibration of the swing preventing weight resonate with each other by reciprocal transfer. 2. A plurality of transport troughs are disposed adjacent to each other in a circumferential direction with the article transport direction being a radial direction, and an inclined plate is mounted on an upper part of each swing prevention weight, and the inclined plate is arranged in the radial direction. 2. The electromagnetic vibration feeder for a combination weigher and the like according to claim 1, wherein said electromagnetic vibration feeders are arranged adjacent to each other in a circumferential direction and have a substantially conical surface on a center portion of a group of transport troughs. 3. A system including a body including a swing prevention weight, a diaphragm spring, and an excitation electromagnet is provided below the transport trough.
3. An electromagnetic vibration feeder for a combination weigher or the like according to claim 1, wherein an upper portion and an inner surface are covered by a dustproof cover and a sealing bellows.