JPH0242654Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a parts feeder with an improved vibration transmission system from a support spring to a bowl.

[Technical background of the invention and its problems] Conventionally, parts feeders used for conveying small parts have structures shown in FIGS. 8 and 9. In FIGS. 8 and 9, 1 is a base, 2 is a plurality of support springs made of leaf springs that are erected on the base 1 so as to be slightly inclined, and 3 is connected to the upper end of these support springs 2. 4 is a track formed on the inner peripheral surface of the bowl 3, 5 is a parts outlet formed on the side of the bowl 3, 6 is an electromagnet provided on the base 1, and 7 is its fixed core. , 8 is a winding, and 9 is a movable iron core provided on the outer bottom surface of the bowl so as to face the fixed iron core 7. In this case, when a voltage is applied to the electromagnet 6, the movable iron core 9 is intermittently attracted by the magnetic attraction force that is generated intermittently according to the power frequency, and the intermittent attraction Due to the operation, the support spring 2 repeatedly bends and springs back to vibrate, and as a result, the bowl 3 vibrates, and the parts inside the bowl 3 are conveyed along the track 4 by the vibrations, and the parts are removed. Exit from exit 5.

However, in such a conventional device, parts sometimes fall off the track 4, and the number of parts transported per unit time is small, in other words, the transport efficiency is low. In this case, the reason why the parts fall off the track 4 is due to its vibration system, which will be described below. That is, electromagnet 6
applies a magnetic attraction force to the movable iron core 9, as the bowl descends, the support spring 2 is deformed from the solid line state in FIG. 9 as shown by the two-dot chain line, and when the magnetic attraction force is released, It elastically returns from the deformed state to the original state shown by the solid line in the figure. In this case, when the support spring 2 is bent and deformed, the bowl 3 is slightly rotationally displaced in the circumferential direction (in the direction of arrow A in FIG. 8) due to the deformation, and when the support spring 2 returns, the bowl 3 is Return displacement in the opposite direction. Now, looking at the displacement characteristics at the connection point X between the upper end of the support spring 2 and the bowl 3 and the radial load force acting on the support spring 2, in FIG. Due to the deformation, the center of the bowl 3 tends to be displaced linearly in the tangential direction from its original position, but since this connection point X is a fixed point at a certain radial distance r of the bowl 3, the center of the bowl Displace on the arc with . Now, connection point X
When the apparent tangential displacement distance is W, at that displacement point, the connecting point Ru. Due to this displacement δ, the support spring 2 receives a radial force F ₁ . This force F ₁ is
It is calculated using the following formula.

F ₁ = δ・8・E・I ₁ /l ₁ ⁴ E...Longitudinal elastic modulus [Kg/mm ² ] I ₁ ...Moment of inertia of area [mm ⁴ ] (I ₁ = b ₁・h ₁ ³ /12) b ₁ ...Thickness of the support spring [mm] h ₁ ...Width of the support spring [mm] l ₁ ...Effective height of the support spring [mm] Now, substituting specific values into the above formula,
If E = 21000, b ₁ = 2.3, h ₁ = 35, and l ₁ = 50, then F ₁ = 2.2 [Kg]. Therefore, in the above configuration, a force of 2.2 kg is applied intermittently to the support spring 2 in the radial direction.

However, since the movable parts of the parts feeder (such as the bowl 3) are usually set to resonate with the power frequency, if the force acting on the support spring 2 is large in this way, the support spring 2 determined by this The natural frequency of the supporting spring 2 approaches the resonance point with the movable part, and the support spring 2 resonates with the movable part.As a result, the radial vibration amplitude at the connecting point The frequency with which parts fall off the track 4 increases, resulting in a problem of reduced parts conveyance efficiency. Incidentally, the amplitude characteristics in each direction of such a conventional bowl are shown in FIG. 4 in relation to the voltage applied to the electromagnet ₆ . H ₁ indicates the amplitude characteristic in the circumferential direction, and characteristic line V ₁ indicates the amplitude characteristic in the vertical direction. Further, the component conveyance efficiency is shown in FIG. 5 in relation to the voltage applied to the electromagnet 6, and in the same figure, the characteristic line _Q1 is the conventional conveyance efficiency characteristic.

[Purpose of the invention] The present invention has been made in view of the above circumstances, and its purpose is to provide a parts feeder that can improve parts conveyance efficiency.

[Summary of the invention] The invention forms a narrow portion in the connecting portion that connects the support spring and the bowl to reduce the load force applied to the support spring in the bowl radial direction, thereby acting on the support spring. This is designed to reduce the vibration amplitude in the radial direction.

[Embodiment of the invention] Below, Figures 1 to 5 are shown for the first embodiment of the invention.
Only the parts that are different from the conventional one will be explained with reference to the drawings.
Reference numeral 10 denotes a connecting plate made of, for example, a steel plate, and one end of this connecting plate is connected to the upper end of each support spring 2, and the other end is connected to the outer bottom of the bowl 3.
As shown in FIG. 3, this connecting plate 10 has a narrow portion 12 formed by forming U-shaped notches 11, 11 on both side edges. In this narrow portion 12, the load force F ₂ on the support spring 2 in the radial direction of the bowl 3 is determined by the following equation.

F ₂ = δ・8・E・I ₂ /l ₂ ⁴ I ₂ =b ₂・h ₂ ³ /12 b ₂ ... Thickness of connecting plate 10 [mm] h ₂ ... Width of narrow part 12 [mm] l ₂ ...Distance from the connection point X with the bowl 3 to the narrow part 12 [mm] Here, in this embodiment, I ₂ /l determines the force F ₂ which is the radial load force on the support spring 2. _twenty ^four
is conventionally set to be smaller than I ₁ /l ₁ ⁴ at the radial load force F ₁ on the support spring 3,
Thus, the load force on the support spring 2 due to the radial displacement amount δ of the connection point X is reduced. Specifically, in this example, the moment of inertia I ₂ (B ₂ · h ₂ ³ /12) and the above distance l ₂ are set to b ₂ = 2.3 h ₂ = 5.0 l ₂ = 15, so that , F ₂ =0.79 [Kg].

As a result, according to this embodiment, the radial load force acting on the upper end of the support spring 2 is reduced to 0.79 kg by the narrow portion 12, and therefore the resonance between the support spring 2 and the bowl 3 is prevented, and the vibration amplitude in the radial direction of the bowl 3 becomes as shown by the characteristic line _R2 in Fig. 4.
significantly smaller. Also, as a result, track 4
It is possible to significantly reduce the number of parts falling off during the process, and the conveyance efficiency can be greatly increased as shown by the characteristic line _Q2 in FIG. In Fig. 4, the characteristic line _H2 represents the vibration amplitude in the circumferential direction in this example.
V ₂ indicates the vibration amplitude in the vertical direction, respectively.

Next, FIGS. 6 and 7 show a second embodiment of the present invention, in which the connecting member 13 serving as the connecting portion is formed into a cross-sectional shape, and its vertical plate portion is defined as the narrow portion 14.

Note that the shape of the narrow portion is not limited to the above embodiments, and various modifications are possible. Further, the connecting portion may be formed integrally with the support spring 3, and in this case, a narrow portion may be formed in the connecting portion of the support spring 3.

[Effects of the Invention] As is clear from the above description, the present invention has an excellent effect in that the radial load force of the support spring can be reduced and the efficiency of conveying parts can be greatly improved.

[Brief explanation of the drawing]

1 to 5 show a first implementation of the present invention, FIG. 1 is a front view of the main part, FIG. 2 is a side view of the main part, FIG. 3 is a bottom view of the main part, FIG. 4 is a vibration amplitude characteristic diagram of each part showing a comparison between this embodiment and a conventional example, and FIG. 5 is a conveyance efficiency characteristic diagram showing a comparison between this embodiment and a conventional example. 6 and 7 are views corresponding to FIG. 1 and 2, respectively, showing a second embodiment of the present invention.
It is a figure equivalent figure. Figure 8 is a perspective view of the whole.
FIG. 9 is a diagram corresponding to FIG. 3 showing a conventional example, and FIG. 10 is a plan view showing the displacement of the connecting point X. In the figure, 2 is a support spring, 3 is a bowl, 4 is a track, 6 is an electromagnet, 10 is a connecting member (connection part), 1
2 is a narrow part, 13 is a connecting member (connecting part), and 14 is a narrow part.

Claims (1)

[Scope of utility model registration request] The bowl is supported by a support spring attached to a base, and the bowl is vibrated by vibrating the support spring,
A parts feeder characterized in that a connecting portion connecting the support spring and the bowl is provided with a narrow portion that reduces a load force applied to the support spring in a radial direction of the bowl.