KR102168190B1 - Apparatus and method for forming steering wheel - Google Patents

Abstract

Disclosed in the present invention is an apparatus for forming a steering wheel. According to one embodiment of the present invention, the apparatus for foam-forming a steering wheel comprises: a foam mold main body having an annular mold for foam-forming the steering wheel provided therein; a gate part provided in the foam-forming main body to inject a raw material into the foam mold; a valve operation part provided in the foam mold main body and including a suction valve for sucking gas generated in the mold and discharging the gas to the outside; a temperature sensor provided between the foam mold and the valve operation part and configured to detect the raw material discharged from the foam mold; and a control part for controlling the valve operation part based on temperature information detected by the temperature sensor and forming time information of the steering wheel.

Description

Steering wheel forming apparatus and method {APPARATUS AND METHOD FOR FORMING STEERING WHEEL}

The present invention relates to an apparatus and method for forming a steering wheel. More specifically, the gas generated during foam molding of the steering wheel is discharged using the shape of overflow, but the amount of overflow is minimized by placing a temperature sensor at the location where the overflow occurs. It relates to a steering wheel forming apparatus and method capable of suppressing the occurrence of a forming part.

The steering wheel is a circular steering device used to change the direction of the vehicle by moving the wheel of the vehicle left and right, and is one of the structures that have the most contact with the driver's body.

Conventional steering wheels are often of PU (Poly Urethane) specification in which the rim is finished with polyurethane foam in the armature core, and the polyurethane foam is molded in the core, and the exterior is finished with leather. Polyurethane foam is an exothermic reaction during foaming in the molding apparatus, and the foaming agent is volatilized by the high temperature inside the foam, and pores are generated on the inner surface of the mold due to foaming pressure. Even if the steering wheel product is molded due to the pores, there is a problem that a partially unmolded part occurs.

The present invention has been devised to solve and improve the conventional problems, and effectively discharges gas generated in the process of manufacturing the steering wheel by the foam molding method to the outside, thereby suppressing the occurrence of unmolded parts by the gas. It is intended to provide a steering wheel forming apparatus and a forming method.

In addition, it is intended to provide a steering wheel forming apparatus and a forming method having a configuration capable of forming and removing overflow, but minimizing the amount of overflow in order to reduce manufacturing cost.

A molding apparatus for foam-molding a steering wheel according to an embodiment of the present invention includes a foam mold main body having an annular mold for foam molding the steering wheel provided therein; A gate part provided in the foam mold main body and for injecting raw materials into the foam mold; A valve operating unit provided in the foam mold body portion and including a suction valve for sucking gas generated in the mold and discharging it to the outside; A temperature sensor provided between the foaming mold and the valve operation unit and configured to detect raw materials discharged from the foaming mold; And a control unit for controlling the valve operation unit based on temperature information detected by the temperature sensor and molding time information of the steering wheel.

In addition, a plurality of valve operation units may be provided, one of which may be provided at a position opposite to the gate unit.

In addition, the gate portion is provided in the vicinity of 6 o'clock in the mold, and three valve operation portions are provided, and may be provided in the vicinity of 3 o'clock, 9 o'clock and 12 o'clock, respectively.

In addition, a plurality of valve operation units may be provided, and a pair of them may be provided at positions corresponding to a thumb rest section of the steering wheel, respectively.

In addition, a plurality of the valve operation units are provided, and between each of the valve operation units and the foaming mold, the valve operation unit and the foaming mold are in communication with each other, so that the raw material filling the foaming mold may be introduced. An additional portion is provided, and the temperature sensor may be provided in the overflow portion.

In addition, the overflow part includes a first part in communication with the mold and into which the raw material discharged from the mold flows in, and a second part in communication with the valve operation part, and the first part and the second part The direction of the silver flow path can be changed.

In addition, the suction valve may be installed inclined with respect to the flow path of the raw material in the overflow part.

In addition, the control unit, when starting the foam molding in the foam mold, controls the suction valve to open the suction valve to start discharging the gas, and the temperature detected by the temperature sensor exceeds a predetermined value. When the temperature is raised, the suction valve may be controlled to prevent the raw material from being discharged to the outside by closing the suction valve.

In addition, when the temperature of the temperature sensor rises above a predetermined value, the control unit may close the suction valve after a predetermined delay time.

In addition, the control unit, when the temperature of the temperature sensor rises above a predetermined value, closes the suction valve and discharges additional gas formed during the cream time of the raw material according to a predetermined pattern. The suction valve can be opened or closed.

In addition, the foaming mold corresponding to the rod portion to which the leather of the steering wheel is coupled is provided with a plurality of rod portion bent portions, and the rod portion bent portion communicates with the foaming mold to prevent non-molding in the rod portion. A raw material inlet having a funnel shape; And an air vent part communicating with the upper end of the raw material inlet part to discharge gas formed at the raw material inlet part to the outside.

A molding method for foam molding a steering wheel according to an embodiment of the present invention includes: a raw material injection step of injecting a raw material into an annular foam mold for molding the steering wheel; A foaming step of foaming the raw material; And a suction step of controlling the opening and closing of the suction valve to discharge the gas generated in the foaming step to the outside and controlling the operation of the vacuum generator, wherein the suction step detects the foaming signal of the raw material, and the suction A first step of opening a valve and starting the operation of the vacuum generator to suck the gas; A second step of detecting the raw material overflowing from the foaming mold based on a temperature sensor signal provided between the foaming mold and the suction valve; And a third step of closing the suction valve and stopping the vacuum generator.

According to the steering wheel molding apparatus and molding method according to an embodiment of the present invention, gas generated by foam molding is discharged to the outside, thereby suppressing the occurrence of an unmolded part by the gas.

In addition, the unmolded part is suppressed by forming and removing overflow, but manufacturing cost can be reduced and generation of environmental waste can be reduced by minimizing the amount of overflowing material.

In addition, by reducing the amount of overflow, the amount of the release agent is reduced, thereby reducing cost and improving environmental problems.

1 is a plan view of a steering wheel forming apparatus according to an embodiment of the present invention.
2 is a view for explaining in detail part II of FIG. 1.
FIG. 3 is a view for explaining in detail a portion of FIG. 1.
4 is a cross-sectional view taken along line AA in FIG. 1.
5 is a plan view of a steering wheel molded according to an embodiment of the present invention.
6 is a view for explaining the shape of a bent portion for forming the rod portion of the steering wheel in the steering wheel forming apparatus according to an embodiment of the present invention.
7 is a flow chart showing a method for forming a steering wheel according to an embodiment of the present invention.
8 is a view for explaining in detail the gas discharge step in FIG.
9 is a view showing a control pattern of a suction valve according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in the drawings, parts not related to the description are omitted in order to clearly describe the embodiments of the present invention.

The terms used in this specification are used only to describe specific embodiments, and are not intended to limit the present invention. Singular expressions may include plural expressions unless the context clearly indicates otherwise.

In the present specification, terms such as "comprise", "have", or "include" are intended to designate the presence of features, numbers, steps, actions, components, parts, or a combination thereof described in the specification. It may be understood that the presence or addition of other features, numbers, steps, actions, components, parts, or combinations thereof, or further features, are not excluded in advance.

In addition, since it does not mean that the objects or effects presented in the present invention should be included in all or only those effects in a specific embodiment, it should not be understood that the scope of the present invention is limited by the specific embodiment. On the other hand, among the technical configurations described in the present invention and the functions exhibited by the technical configurations, the technical configurations and functions that are widely known and applied will be omitted from the detailed description thereof.

In addition, the following embodiments are provided to more clearly describe to those with average knowledge in the art, and the shape and size of elements in the drawings may be exaggerated for clearer explanation.

Hereinafter, a preferred embodiment according to the present invention will be described with reference to the accompanying drawings.

1 is a plan view of an apparatus for forming a steering wheel according to an embodiment of the present invention, and FIG. 2 is a view for explaining part II of FIG. 1 in detail. 3 is a view for explaining in detail the portion Ш of FIG. 1, and FIG. 4 is a cross-sectional view taken along line A-A of FIG. 1.

1 to 3, a steering wheel forming apparatus 100 according to an embodiment of the present invention is a manufacturing apparatus provided for foam molding a steering wheel of a vehicle. In the steering wheel forming apparatus 100 according to the present embodiment, when a raw material mixed with a resin and a foaming agent such as polyurethane (PU) foam is injected into the mold body 120, the steering wheel ( 10) is prepared.

The steering wheel forming apparatus 100 includes a mold main body 120, a gate part 126, a valve operation part 140 and 180, a temperature sensor 172 and 183, and a control unit 130.

The mold main body 120 is a place where a raw material for manufacturing the steering wheel 10 is introduced and foamed therein, and an approximately annular foam mold 124 corresponding to the shape of the steering wheel 10 is provided. . When the armature 20 for manufacturing the steering wheel 10 is positioned in the foaming mold 124 of the mold main body 120, and the mold main body 120 composed of upper and lower parts is vertically coupled, the gate A raw material in which a resin and a foaming agent are mixed may be injected in the direction (I) through the portion 126. When the injection of the raw material is completed and molding starts, the raw material undergoes an exothermic reaction and the temperature of the raw material is increased while being molded.

A plurality of valve operation units 140 and 180 may be provided, and in the present embodiment may be provided near the 3 o'clock, 9 o'clock, and 12 o'clock directions based on the shape of the steering wheel 10. The valve operation units 140 and 180 may include suction valves 176 and 186 for suctioning and discharging the gas generated when the raw material is foamed using a vacuum by a vacuum generator (not shown). The suction valves 176 and 186 may be of a solenoid valve type, for example, and opening and closing may be performed automatically. The valve operation unit 140 may be provided at positions symmetrical to each other around 3 o'clock and 9 o'clock of the steering wheel 10.

In one embodiment, in the foam mold 124, the valve operation unit 140 is provided on the left and right so as to communicate with the foam mold 124 at a position corresponding to the vicinity of the thumb rest of the steering wheel 10 Can be. The thumb rest refers to the shape of the skin of the bottleneck section present in the grip body of the steering wheel 10, in the vicinity of the user's thumb touching the steering wheel 10 when the user grips the steering wheel 10. As can be seen from the flow direction (I), the flow of the raw material is concentrated during foaming due to the characteristics of the bottleneck section. Accordingly, pupils and air bubbles may occur due to the retention of gas generated during foaming. Accordingly, in order to suppress the pupil and remove air bubbles, the valve operation unit 140 may be disposed near the thumb rest so that the generated gas can be effectively introduced.

Meanwhile, the valve operation unit 180 may be located near 12 o'clock of the steering wheel 10, that is, opposite to the gate unit 126. That is, the valve operation unit 180 may be located where the raw material flows into the gate unit 126 and moves the farthest. The 12 o'clock part of the steering wheel 10 is also called a weld part, and the shape of the grip body of the steering wheel 10 is symmetrically left and right, and it is the farthest from the injection part of the raw material due to the circular skin characteristics. Located. Accordingly, this is a place where the gas generated in the mold may be retained and thus an unmolded part may occur. Therefore, by providing the valve operation unit 180 around 12 o'clock, the generated gas can be effectively introduced and discharged to the outside.

The temperature sensors 172 and 183 are provided between the foam mold 124 and the valve operation parts 140 and 180, respectively, and are provided to first fill the foam mold 124 and detect overflowing raw materials. Before the raw material is first introduced into the foaming mold 124, the temperature sensors 172 and 183 are before contacting the raw material, so that a relatively low temperature such as room temperature can be maintained. Thereafter, when the raw material flows into the foaming mold 124, the foaming mold 124 is first filled, and after the foaming mold 124 is filled, an overflow part 142 that is naturally in communication with the valve operation part and the foaming mold 124 , 182). The temperature sensors 172 and 183 are provided in the overflow units 142 and 182 to fill the foaming mold 124 and detect the raw material overflowing. That is, in this embodiment, the control unit 130 may be connected to the connector 122 of the mold main body 120, and a situation in which the raw material overflows may be identified using the temperature sensors 172 and 183. Accordingly, the amount of the raw material overflow can be adjusted according to the installation position of the temperature sensors 172 and 183.

The control unit 130 controls the valve operation units 140 and 180 to open and close the suction valves 176 and 186 based on the temperature information sensed from the temperature sensors 172 and 183 and the forming time information of the steering wheel. Can be controlled.

Referring to FIG. 2, a valve operation unit 140 provided on a thumb rest 14 located near 3 o'clock of the steering wheel 10 is shown. The valve operation unit 140 includes a suction valve 176 capable of operating in a solenoid manner. When the suction valve 176 is opened, the raw material may be introduced toward the suction valve 176 by vacuum. After the raw material flowing into the foaming mold 124 fills the foaming mold 124, it may flow into the overflow part 142. The overflow part 142 may be composed of two parts, a first part 142a and a second part 142b. The first part 142a communicates with the foaming mold 124 so that the raw material overflowing from the foaming mold 124 may be introduced. The second part 142b may be different from the first part 142a by changing the direction of the flow path through which the raw material flows, and may communicate with the suction valve 176 of the valve operation unit 140. In one embodiment, the temperature sensor 172 may be located on the first part 142a, that is, upstream of the overflow part 142. Accordingly, when the raw material reaches the temperature sensor 172, the temperature increases due to an exothermic reaction, and the temperature measured by the temperature sensor 172 may increase due to contact with the raw material. The temperature measured by the temperature sensor 172 is transmitted to the control unit 130. When the foam molding starts in the foam mold 124, the control unit 130 may open the suction valve 176 to start discharging the gas, and the temperature value detected by the temperature sensor 172 is equal to or greater than a predetermined value. If it is determined that it is increased, the suction valve 176 may be controlled to close. Accordingly, the overflowed raw material may be prevented from being discharged to the outside through the opened suction valve 176, and only the gas generated by foaming may be discharged first. On the other hand, when the temperature measured by the temperature sensor 172 rises above a predetermined value, the controller 130 may close the suction valve 176 after a predetermined delay time without immediately closing the suction valve 176. have. By adjusting the amount of the raw material that overflows, it is possible to prevent the unmolded portion of the steering wheel 10 from being generated, and prevent an increase in the amount of the raw material that overflows.

3 is a view for explaining in detail a portion of FIG. 1, and FIG. 4 is a cross-sectional view taken along line A-A of FIG. 1.

Referring to FIGS. 3 and 4, a valve operation unit 180 provided near 12 o'clock of the steering wheel 10 is shown. The valve operation unit 180 includes a suction valve 186 that can be operated in a solenoid manner, and when the suction valve 186 is opened from the suction hole H, the raw material is converted to the suction valve 186 by vacuum. It can be introduced toward. After the raw material flowing into the foaming mold 124 fills the foaming mold 124, it may flow into the overflow part 182. The overflow part 182 may be composed of two parts, a first part 182a and a second part 182b. The overflow part 182 provided near 12 o'clock is a differently elongated annular shape as compared to the overflow part 142 provided at 3 o'clock and 6 o'clock. The first part 182a communicates with the foaming mold 124 so that the raw material overflowing from the foaming mold 124 may be introduced. The second part 182b is provided on the opposite side to the first part 182a, and the direction of the flow path through which the raw material flows may be changed and may be different, and may communicate with the valve 186 of the valve operation part 180 . In one embodiment, the temperature sensor 183 may be located on the upstream side of the first portion 182a, that is, the overflow portion 182. Accordingly, when the raw material reaches the temperature sensor 183, the temperature increases due to an exothermic reaction, and the temperature measured by the temperature sensor 183 may increase due to contact with the raw material. The temperature measured by the temperature sensor 183 is transmitted to the control unit 130, and the control unit 130 opens the suction valve 186 when it is determined that the temperature value detected by the temperature sensor 183 has increased by a predetermined value or more. Can be controlled to close. Accordingly, the overflowed raw material may be prevented from being discharged to the outside through the opened suction valve 186, and only the gas generated by foaming may be discharged first.

Meanwhile, when the temperature measured by the temperature sensor 183 rises above a predetermined value, the control unit 130 may close the suction valve 186 after a predetermined delay time without immediately closing the suction valve 186. have. By adjusting the amount of the raw material that overflows, it is possible to prevent the unmolded portion of the steering wheel 10 from being generated, and prevent an increase in the amount of the raw material that overflows.

Referring to FIG. 4, the suction valve 186 is a solenoid type, and may be moved by a control signal from the controller 130 to open or close the suction hole H. The suction valve 186 may be installed inclined with respect to the overflow part 182. Since the suction valve 186 is installed inclined downward with respect to the overflow part 182, it is possible to prevent the raw material from clogging the suction valve 186 and to prevent a decrease in the amount of gas intake due to vacuum. In this embodiment, the suction valve 186 is provided to be inclined by approximately 30 degrees, but is not limited thereto. A vacuum unit 125 in which a vacuum is formed by a vacuum generator (not shown) such as a vacuum pump is formed under the suction valve 186, and gas generated by the foaming of the raw material when the suction valve 186 is opened. Can be introduced.

5 is a plan view of a steering wheel molded according to an embodiment of the present invention, and FIG. 6 is a shape of a bent portion for forming a rod portion of a steering wheel in a steering wheel forming apparatus according to an embodiment of the present invention. It is a drawing for explanation.

Referring to FIG. 5, the steering wheel 10 is manufactured by the steering wheel forming apparatus 100 shown in FIG. 1, and the steering wheel 10 includes a gate portion 126 and an overflow portion 142, 182. It may include overflow shapes 17, 15, 16 molded together in each. When the steering wheel 10 is formed, the overflow shapes 17, 15, and 16 may be removed through a cutting process along the cutting line C.

Meanwhile, the steering wheel 10 may be provided with a plurality of rods 12 to which leather is coupled during manufacture. However, in the portion where the rod portion 12 is formed, a problem occurs in that the gas generated in the process of progressing from cream time to gel time due to the material properties of the raw material cannot be completely removed. Accordingly, there may be a problem in that the steering wheel is not molded in the rod part 12. In order to prevent this, in this embodiment, the rod portion bent portions 127 and 128 may be provided to improve the molding of the rod portion 12 at each position corresponding to the rod portion 12 of the steering wheel 10. . The rod portion bent portion (127, 128) communicates with the foam mold 124 and has a funnel shape and a raw material inlet portion 127 and a raw material inlet portion 127 to prevent unmolding in the rod portion 12 It may include an air vent unit 128 for preventing air bubbles from being formed by discharging the gas formed in the raw material inlet 127 to the outside in communication with the upper end of the. The diameter of the air vent part 128 is smaller than the average diameter of the raw material inlet part 127 and communicates with the outside of the mold body part 120 to discharge the gas to the outside.

7 is a flowchart illustrating a method of forming a steering wheel according to an embodiment of the present invention, and FIG. 8 is a view for explaining in detail a gas discharge step in FIG. 7.

Referring to FIG. 7, in the steering wheel shaping method (S100) according to an embodiment of the present invention, a raw material is first injected into the annular foaming mold 124 of the steering wheel shaping apparatus 100 in step S110. . In step S120, the raw material injected into the foaming mold 124 is foamed. Next, in step S130, the control unit 130 controls the suction valves 176 and 186 to discharge the gas formed by the foamed raw material to the outside. Here, the steps S120 and S130 are not sequentially performed, but may be performed simultaneously.

Referring to FIG. 8, the gas discharge step (S130) of FIG. 7 is shown in more detail. First, in step S131, the control unit 130 opens the suction valves 176 and 186 by detecting the foaming signal. The foaming signal may be a signal generated simultaneously with the injection of the raw material. In step S132, the control unit 130 operates the vacuum generator with the opening of the suction valves 176 and 186 to start discharging the gas generated in the foaming mold 124 to the outside by using a vacuum. have. In step S133, the control unit 130 may detect that the raw material is introduced into the overflow units 142 and 182 using the temperature sensors 172 and 183. In a subsequent step (S134), the controller 130 may close the suction valves 176 and 186 and stop the vacuum generator.

9 is a view showing a control pattern of a suction valve according to an embodiment of the present invention.

Referring to FIG. 9, when the temperature of the temperature sensors 172 and 183 rises above a predetermined value, the control unit 130 closes the suction valves 176 and 186. However, even afterwards, additional gas may be generated during the cream time of the raw material. The controller 130 may additionally open or close the suction valves 176 and 186 according to a predetermined pattern to discharge the additionally generated gas. In this case, the control unit 130 may set the opening and closing times differently according to the number of cycles (steps) according to the positions of the suction valves 176 and 186.

According to the steering wheel molding apparatus and molding method according to the above-described embodiment, gas generated by foam molding is discharged to the outside, so that the occurrence of an unmolded part by the gas can be suppressed. In addition, the unmolded part is suppressed by forming and removing overflow, but manufacturing cost can be reduced and generation of environmental waste can be reduced by minimizing the amount of overflowing material. In addition, by reducing the amount of overflow, the amount of the release agent is reduced, thereby reducing cost and improving environmental problems. For example, as a result of applying it to the mass production of steering wheels of various vehicle types currently being mass-produced, it is possible to achieve a material saving effect of about 30% by reducing the discharge amount of 90g to 130g compared to the discharge amount of raw material (about 400 to 430g) before application. there was.

Although the exemplary embodiments of the present invention have been described in detail above, those of ordinary skill in the art to which the present invention pertains will understand that various modifications may be made to the above-described embodiments without departing from the scope of the present invention. .

Therefore, the scope of the present invention is limited to the described embodiments and should not be determined, and should not be determined by the claims to be described later, but also by those equivalents to the claims.

10: steering wheel 12: stitch
15, 16, 17: overflow shape 20: armature
14: thumb rest 100: steering wheel shaping device
120: mold main body 124: foaming mold
140, 180: valve operating part 142, 182: overflow part
172, 183: temperature sensor 176, 186: suction valve

Claims (7)

As a molding device for foam molding a steering wheel,
A foam mold main body having an annular mold for foam molding the steering wheel provided therein;
A gate part provided in the foam mold main body and for injecting raw materials into the foam mold;
A valve operating unit provided in the foam mold body portion and including a suction valve for sucking gas generated in the mold and discharging it to the outside;
A temperature sensor provided between the foaming mold and the valve operation unit and configured to detect raw materials discharged from the foaming mold; And
A control unit for controlling the valve operation unit based on temperature information detected by the temperature sensor and molding time information of the steering wheel; and
A plurality of rod portion vent portions are provided in the foam mold corresponding to the rod portion to which the leather of the steering wheel is coupled,
The rod portion bent portion,
A raw material inlet part communicating with the foaming mold and having a funnel shape to prevent unmolding in the rod part; And
And an air vent part communicating with the upper end of the raw material inlet part to discharge gas formed at the raw material inlet part to the outside.
The method of claim 1,
The plurality of valve operation units are provided, one of which is provided at a position opposite to the gate unit.
The method of claim 2,
The gate part is provided near 6 o'clock in the mold
The three valve operation units are provided, and the steering wheel forming apparatus is provided around 3 o'clock, 9 o'clock and 12 o'clock, respectively.
The method of claim 2,
A plurality of valve operation units are provided, one of which is provided at a position corresponding to a thumb rest section of the steering wheel, respectively.
The method of claim 1,
The control unit,
When starting the foam molding in the foam mold, the suction valve is opened to start the discharge of the gas, and
If the temperature detected by the temperature sensor rises above a predetermined value, the suction valve is controlled to prevent the raw material from being discharged to the outside by closing the suction valve.
The method of claim 5,
The control unit,
When the temperature of the temperature sensor rises above a predetermined value, the suction valve is closed after a predetermined delay time.
The method of claim 5,
The control unit,
When the temperature of the temperature sensor rises above a predetermined value, the suction valve is closed,
Steering wheel forming apparatus to open or close the suction valve according to a predetermined pattern so as to discharge additional gas formed during the cream time of the raw material.

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