JP2016117445A - Vehicular component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular component having no edge shape to be a crack starting point.SOLUTION: There is provided a vehicular component 1 in which a fitting part 3 and a fitting peripheral part 5 of a body part 2 are composed as an unfoamed solid layer 11; a portion other than the fitting peripheral part of the body part 2 is composed of skin layers 6, 7 composing the surface and rear face parts and a foam layer 8; and an edge shape to be a crack starting point does not exist. The vehicular component 1 is molded by using a molding material comprising a synthetic resin material, a high-hardness fiber such as a glass fiber or carbon fiber, and mica or talc by a core back molding method. The portion other than the fitting peripheral part of the body part 2 is composed of the skin layers 6, 7 composing the surface and rear face parts and the foam layer 8, and the fitting part 3 and the fitting peripheral part 5 of the body part 2 are composed into an unfoamed solid layer 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle component made of a synthetic resin molded by a core back molding method.

  The under cover 61 disclosed in Patent Document 1 will be described with reference to FIG. The under cover 61 shown in FIG. 12 is a vehicle component made of a synthetic resin molded by a core back molding method, and includes a main body portion 62, a mounting portion 63, and a mounting hole portion 64.

  With reference to FIG. 13, the internal structure of the main-body part 62 and the attaching part 63 of the undercover 61 is demonstrated. FIG. 13 shows a part of the internal structure of the under cover 61 taken out from the mold 73 after the molding shown in FIG. The main body 62 is composed of skin layers 65; 66 that constitute the front and back surfaces, and a foam layer 67 that constitutes an intermediate portion between the skin layers 65; 66. The attachment portion 63 includes an attachment hole portion 64, a cylindrical wall portion 68, and a top wall portion 69. The cylindrical wall portion 68 is shaped so as to protrude from the main body portion 62 to the front side or the back side, and is a slow layer with a small amount of foaming that constitutes an intermediate portion between the skin layers 70 and 71 constituting the front and back portions and the skin layers 70 and 71. It comprises a variable layer 72. The top wall portion 69 is shaped so as to close the opening portion that protrudes from the main body portion 62 of the cylindrical wall portion 68 to the maximum, and is an unfoamed solid layer 79. The mounting hole 64 is shaped to penetrate in and out at the center of the top wall 69.

  The under cover 61 shown in FIG. 13 is running when the under cover 61 is attached to an automobile because the boundary portion 80 between the top wall portion 69 and the cylindrical wall portion 68 of the attachment portion 63 has an edge shape. Due to the vibration and impact, the edge-shaped boundary portion 80 becomes a starting point of occurrence of cracking, and is easily cracked.

  A core back molding method for molding the under cover 61 will be described with reference to FIGS. The molding die 73 shown in FIG. 14 includes a fixed die 74, a movable die 75, and a slide die 76. The fixed die 74 is a die attached to the injection unit side of an injection molding machine that performs the core back molding method, and includes a mounting hole projection 77. The mounting hole projection 77 can also be applied to the slide mold 76. The movable mold 75 is a mold that is mounted on the mold clamping unit side of the injection molding machine. The slide mold 76 is a mold attached to the ejector portion of the mold clamping unit. FIG. 14 shows the internal molding in a state where the molding die 73 is clamped and the fixed die 74, the movable die 75, and the slide die 76 form the molding space 78.

  FIG. 15 shows that after the molding material is injected into the molding space 78 and the skin layers 65, 66, 70, 71 are formed on the main body 62 and the cylindrical wall 68, the slide mold 76 is projected from the ejector portion. Thus, the distance of the molding space 78 between the fixed mold 74 and the fixed mold 74 is kept constant so as to be the same as the distance at the time of mold clamping, and the movable mold 75 receives the core back from the mold clamping unit and molds with the fixed mold 74. The model is shown in which the distance of the space 78 is set back to be larger than the distance at the time of mold clamping, the foam layer 67 is formed on the main body 62, and the gradual change layer 72 is formed on the cylindrical wall 68.

JP 2014-121793 A

  The present invention has been made in view of the above-described background art. A vehicle component in which an attachment portion and a body portion around the attachment portion are formed in an unfoamed solid layer and an edge shape that does not have an edge shape as a crack starting point is provided. The purpose is to provide.

  The present invention includes a main body portion and a mounting portion formed by a core back molding method using a molding material made of a synthetic resin material, high-hardness fibers, and mica or talc, and the mounting portion is on the front side or the back side from the main body portion. A vehicular component having a protruding cylindrical wall portion and a top wall portion that closes an opening protruding from the main body portion of the cylindrical wall portion to the maximum, and the mounting portion and the portion around the mounting portion of the main body portion are unfoamed It is constituted as a solid layer, and the part other than the part around the attachment part of the main body part is composed of a skin layer constituting the front and back parts and a foam layer constituting an intermediate part between the skin layers. .

  The present invention is formed by a core back molding method using a molding material composed of a synthetic resin material, high-hardness fibers, and mica or talc, so that it has light weight, high rigidity, and anti-pitting performance, and has an attachment portion and a main body. The mounting peripheral part of the part is configured as an unfoamed solid layer, and the part other than the mounting peripheral part of the main body part is composed of a skin layer that constitutes the front and back parts, and a foam layer that constitutes an intermediate part between the skin layers As a result, there is an effect that there is no edge shape as a crack starting point. It is also applicable that the high-hardness fiber is a glass fiber, and the synthetic resin material is made of a polyolefin resin, or the polyolefin resin is a polypropylene resin, a polyethylene resin, or a mixed resin of a polypropylene resin and a polyethylene resin. It is also applicable to be composed of any one of them.

  In the present invention, if a rubber additive is added to the molding material, the cold shock resistance is improved, and if mica or talc is added, warping of the molded product can be prevented.

  In the present invention, if the synthetic resin material is mixed in the range of 60 to 90 weight percent, the glass fiber is 5 to 20 weight percent, mica or talc is 0 to 20 weight percent, and the sum of the mixing ratio is 100 weight percent It has the effect of having light weight, high rigidity and chipping resistance. In the present invention, the weight of the protective device for both is 1400 to 2000 g / m2, the thickness of the skin layer is 0.2 to 0.5 mm, and the thickness of the vehicle component is 3 to 5 mm. Thus, warping of vehicle parts can be prevented.

  In the present invention, if the foam layer has open cells, weight reduction is promoted.

  In the present invention, if the removal portion is provided in the skin layer, the sound absorbing effect is improved.

Sectional drawing which showed the principal part of the undercover which concerns on the form for inventing. Sectional drawing which showed the clamping state of the shaping | molding die of the undercover which concerns on the form for inventing. Sectional drawing which showed the shaping | molding state of the shaping | molding die of the undercover which concerns on the form for implementing invention. The schematic diagram which showed in plan view the undercover which concerns on the form for inventing. The figure which image | photographed the cross section of the main-body part of the undercover which concerns on the form for inventing with the digital camera. The schematic diagram which showed the internal structure of FIG. The schematic diagram which shows the measuring method of the cold shock resistant performance of the undercover which concerns on the form for inventing. The table | surface which showed the result of the measurement of the cold impact resistance performance of the undercover which concerns on the form for inventing. The chart which showed the formula of the sound absorption structure model of the undercover concerning the form for inventing, and its resonant frequency. The figure which showed the measuring device which measures the sound absorption effect of the undercover which concerns on the form for inventing, a test body shape, and a measurement material. The line graph which shows the result of measuring the sound absorption effect of the undercover which concerns on the form for inventing. The schematic diagram which showed the conventional undercover in the top view. Sectional drawing which showed the principal part of the conventional undercover. Sectional drawing which showed the clamping state of the shaping | molding die of the conventional undercover. Sectional drawing which showed the shaping | molding state of the shaping | molding die of the conventional undercover.

  With reference to FIG. 5, an under cover 1 will be described as an example of a vehicle component made of a synthetic resin molded by a core back molding method according to an embodiment for carrying out the invention. The under cover 1 shown in FIG. 1 includes a main body portion 2, an attachment portion 3, an attachment hole portion 4, and an attachment peripheral portion 5.

  With reference to FIG. 1, the internal structure of parts other than the attachment peripheral part of the main body part 2 according to the embodiment for carrying out the invention, the attachment part 3, the attachment hole part 4, and the attachment peripheral part 5 will be described. The part other than the attachment peripheral part of the main body part 2 is the remaining part excluding the attachment peripheral part 5 from the main body part 2, and is between the skin layers 6 and 7 constituting the front and back parts and the skin layers 6 and 7. It is comprised from the foaming layer 8 which comprises an intermediate part.

  The attachment portion 3 includes an attachment hole portion 4, a cylindrical wall portion 9, and a top wall portion 10. The mounting hole 4 is shaped to penetrate inside and outside at the center of the top wall 10. The cylindrical wall portion 9 is shaped to protrude from the main body portion 2 to the front side or the back side. The top wall portion 10 is shaped to block the opening portion that protrudes from the main body portion 2 of the cylindrical wall portion 9 to the maximum. The attachment peripheral portion 5 is a model that extends to the main body portion 2 so as to surround the cylindrical wall portion 9. The mounting peripheral portion 5, the cylindrical wall portion 9, and the top wall portion 10 are unfoamed solid layers 11.

  Therefore, the attachment part 3 and the attachment peripheral part 5 of the main body part 2 are configured as an unfoamed solid layer 11, and the parts other than the attachment peripheral part of the main body part 2 constitute the skin layers 6 and 7 and the foam layer that constitute the front and back surfaces. By being comprised from 8, the undercover 1 without the edge shape used as a crack starting point can be provided.

  A core back molding method for molding the undercover 1 will be described with reference to FIGS. The molding die 12 shown in FIG. 2 includes a fixed die 13, a movable die 14, and a slide die 15. The fixed mold 13 is a mold mounted on the side of an injection unit of an injection molding machine that performs the core back molding method, and includes a mounting hole projection 16. The mounting hole projection 16 can also be applied to a slide mold. The movable mold 14 is a mold mounted on the mold clamping unit side of the injection molding machine. The slide mold 15 is a mold attached to the ejector portion of the mold clamping unit, and has a shape corresponding to the attachment portion 3 and the attachment peripheral portion 5. FIG. 2 shows the internal molding in a state where the mold 12 is clamped and the fixed mold 13, the movable mold 14, and the slide mold 15 form the molding space 17.

  FIG. 3 shows that after the molding material is injected into the molding space 17 and the skin layers 6 and 7 are formed in portions other than the mounting peripheral portion of the main body 2, the slide die 15 protrudes from the ejector portion and is fixed. The distance between the molding space 17 and the mold 13 is kept constant to be the same as the distance at the time of clamping, and the molding space between the movable mold 14 and the fixed mold 13 receives the core back from the clamping unit. The foamed layer 8 is formed between the skin layers 6 and 7 corresponding to the fixed mold 13 and the movable mold 14 in the molding space 17 by retreating so that the distance 17 is larger than the distance at the time of clamping. 3 shows a modeling in which the solid layer 11 is formed in a portion corresponding to the fixed mold 13 and the slide mold 15 of the molding space 17.

  Therefore, the under cover 1 as a molded product taken out from the mold 12 after molding in FIG. 3 is a boundary portion between the mounting peripheral portion 5 and a portion other than the mounting peripheral portion of the main body 2 as shown in FIG. Therefore, when the under cover 1 is attached to an automobile, it is difficult to crack even if it receives vibration or impact during traveling.

  With reference to FIG. 5, FIG. 6, the internal structure of parts other than the attachment periphery part of the main-body part 2 is demonstrated. The portion other than the attachment peripheral portion of the main body portion 2 shown in FIG. 5 includes a foam layer 8 wrapped with skin layers 6 and 7 having no air permeability on the surface. The foam layer 8 is a cavity made of open cells in which high-hardness fibers 21, synthetic resin material 22, and mica 23 are mixed. Therefore, the undercover 1 is improved in light weight, high rigidity, pitting resistance, and cold shock resistance. As the high-hardness fiber 21, glass fiber or carbon fiber can be applied.

  For example, the weight of the under cover 1 is 1400 to 2000 g / m 2, the thickness 24 of the under cover 1 is 3 to 5 mm, the thickness 25 of the skin layers 6 and 7 is 0.2 to 0.5 mm, and the thickness 27 of the foam layer 8 is 2 To 4.6 mm. As the high-hardness fiber 21, by using a glass fiber having a diameter of 8 to 13 μm and a length of 5 to 15 mm, rigidity for maintaining the shape can be secured, and impact resistance performance in cold weather can be improved. .

  As the high hardness fiber 21, a glass fiber having a diameter of 10 μm and a length of 10 mm was used. Mica 23 having a particle size of 10 to 60 μm was used. A chemical foaming agent was used as the foaming agent. Since the foaming agent becomes a gas during the molding process, the undercover 1 after molding has a cavity made of open cells as a foamed mark of the foaming agent.

  As shown in FIG. 6, the skin layers 6 and 7 are formed in a sheet-like shape having no air permeability, in which high-hardness fibers 21, synthetic resin materials 22, and mica 23 are mixed. The foamed layer 8 is a cavity composed of open cells in which the synthetic resin material 22 and mica 23 exist at the intersections between the surfaces of the high hardness fibers 21 and the high hardness fibers 21 and the bubbles are connected to each other. Note that the foam layer 8 can be applied even if it is a cavity made of closed cells, but if it is open cells, weight reduction is promoted more than closed cells.

  As the synthetic resin material 22 in the skin layers 6, 7 and the foamed layer 8, any one of polypropylene resin, polyethylene resin, or a mixture of polypropylene resin and polyethylene resin is used. A resin obtained by mixing a polypropylene resin and a polyethylene resin has improved cold shock resistance at −30 ° C. as compared with a polypropylene resin. The skin layers 6 and 7 and the foamed layer 8 can be handled by changing the additive depending on the required performance of the undercover, such as using a rubber additive or talc instead of mica. When a rubber additive is used, the cold shock resistance is improved. When mica or talc is used, warpage of the undercover 1 can be prevented.

When the shape and rigidity of the under cover 1 according to the embodiment for carrying out the invention are the same as the shape and rigidity of the under cover 1, the weight of the under cover 1 according to the embodiment for carrying out the invention is 1400 to 2000 g / m ² , The proportional weight was 2200-2600 g / m ² . Therefore, it can be understood that the undercover 1 according to the embodiment for carrying out the invention is proportional, that is, lighter than the conventional undercover.

As described above, in the undercover 1 according to the embodiment for carrying out the invention, the high-hardness fiber 21 is a glass fiber having a diameter of 10 μm and a length of 10 mm, and the mica 23 has a particle diameter of 10 to 60 μm. The under cover 1 has a weight of 1400 to 2000 g / m ² , the skin layers 6 and 7 have a thickness 25 of 0.2 to 0.5 mm, and the under cover 1 has a thickness 24 of 3 to 5 mm. The under cover 1 is light in weight, can secure cold shock resistance and rigidity, and does not warp the under cover 1.

  If the thickness of the under cover 1 is less than 3 mm, the under cover 1 is warped. If the thickness of the under cover 1 exceeds 5 mm, the foamed layer 8 is too thick and the chipping resistance of the under cover 1 is reduced. Cold shock resistance decreases.

  With reference to FIG. 7, the cold shock resistance test will be described. In the cold shock resistance test, the test specimen and the proportional specimen were used. The test specimen is a square plate having the structure of the undercover 1 according to the embodiment for carrying out the invention. The contrast test piece is a square plate having the structure of the conventional example. The surface (plate surface) of the target specimen and the proportional specimen are the same size.

First, a test piece 31 corresponding to each of the subject test piece or proportional test piece is supported by a pair of fixed frames 32 and 33 from above and below. The fixed frames 32 and 33 have a shape surrounding a 135 mm × 195 mm square space. Next, the lower fixing frame 33 is fixed on a surface plate (not shown) of the test apparatus. Then, the weight 34 of the test apparatus was dropped to the center of the test piece 31 inside the fixed frame 32, and the height of the weight 34 when the test piece 31 was cracked was measured. The test was conducted by setting the temperature of the test place where the test apparatus was installed to 23 ° C and -30 ° C. As the weight 34, a 1.5 kg cylindrical iron-made one was used. The area of the lower surface 35 that collides with the test piece of the weight 34 is 706.9 mm ² .

  With reference to FIG. 8, the results of the cold shock resistance test will be described. As shown in FIG. 8, at room temperature of 25 ° C., the subject test piece cracked when the weight was dropped from a height of 450 mm, and the crack occurred when the weight was dropped from a height of 300 mm. Further, at room temperature-30 ° C., the test piece subject to the present invention was cracked when the weight was dropped from a height of 300 mm, and the comparative test piece was cracked starting from the rib when the weight was dropped from a height of 200 mm. .

  Considering the results of the test shown in FIG. 8, in the cold shock resistance performance, the present test piece corresponding to the undercover 1 according to the embodiment for carrying out the invention is higher than the comparative test piece corresponding to the conventional undercover. It became.

  With reference to FIG. 9 thru | or FIG. 10, the sound absorption effect using the sound absorption principle of the Helmholtz resonator with respect to the undercover 1 which concerns on the form for inventing is demonstrated. First, referring to FIG. 9, the sound absorption structure model and the equation for obtaining the resonance frequency will be described. The sound absorbing structure model has a structure in which a removal portion 36 is formed on the skin layers 6 and 7 of the under cover 1 according to the embodiment for carrying out the invention.

  When the thickness of the skin layers 6 and 7 is L, the volume of the foam layer 8 is V, the surface area of the removal portion 36 is S, and the tube end correction coefficient is δ, the foam layer 8 is obtained from the equation for obtaining the resonance frequency in FIG. The resonance frequency f in the cavity is obtained. That is, when sound enters the cavity of the foamed layer 8 from the outside of the sound absorbing structure model via the removal part 36, the air in the cavity acts as a spring, and the air in the removal part 36 vibrates violently, thereby causing the foamed layer 8 to vibrate. A large sound absorption effect due to frictional loss occurs at the resonance frequency f due to the spring of this and the air mass of the removal portion 36.

  In FIG. 10, the measurement of the sound absorption effect will be described by taking, as an example, normal incidence sound absorption coefficient measurement using a measuring apparatus based on the ISO10534-2 standard. The cylinder 41 of the measuring device has a structure in which one end is closed and the other end is closed by a lid 43 to which a test body 42 is attached. In the measurement method, the sound 45 emitted from the power supply 44 is picked up by the microphone 46, and the sound 47 reflected from the test body 42 is picked up by the microphone 48.

  As the test body 42, a disk-shaped low-frequency test body 49 having the structure of the undercover 1 according to the embodiment for carrying out the invention and a test body (not shown) without the removal portion 36 were prepared. The low-frequency test body 49 has a structure in which the diameter is 100 mm, the thickness is 5.0 mm, the number of removal portions 36 is one in the center, and the outer peripheral surface of the skin layer is closed.

  Further, as the test body 42, a non-foamed measurement sample 51 having no removal portion 36, a measurement sample 52 having a removal portion 36 having a diameter of 7 mm, and a measurement sample 53 having a removal portion 36 having a diameter of 10 mm are prepared, and the sound absorption effect is obtained. Measurements were made. The shape of the measurement samples 51 to 53 is the same as that of the test body 42, and has a diameter of 100 mm and a thickness of 5.0 mm. That is, the test body 42 and the measurement samples 51 to 53 have the same shape.

  With reference to FIG. 11, the measurement result of the sound absorption effect in the measurement samples 51 to 53 will be described. Considering FIG. 11, there is an effect of gently absorbing sound around the specific frequency (resonance frequency f). The specific frequency varies depending on the hole diameter, internal volume, hole pitch, and the like, as in the formula of FIG. The test targets automobile tire noise, and targets 800 to 1000 Hz as a specific frequency.

  In the undercover 1 according to the embodiment for carrying out the invention, the thickness and length of the glass fiber as the high-hardness fiber 21 shown in FIG. 5 are not limited to the numerical values described in the paragraph 0029. For example, the present invention can be applied even when the thickness is 8 to 13 μm and the length is 5 to 15 mm. However, in the glass fiber as the high-hardness fiber 21, when the diameter is less than 8 μm and the length is less than 5 mm, the cold impact resistance and rigidity are improved more than the thickness is 8 to 13 μm and the length is 5 to 15 mm. The effect is reduced. In the glass fiber as the high-hardness fiber 21, when the diameter exceeds 13 μm, the molding material poured into the molding die is difficult to flow, and when the molding material is heavy and the length exceeds 15 mm, the molding poured into the molding die There are disadvantages that the material is difficult to flow, the molding material is heavy, and the glass fiber is easily cut in the molding machine cylinder.

  In addition to hydrazodicarbonamide (HDCA), blowing agents include dinitrosopentanemethylenetetramine (DPT), azodicarbonamide (ADCA), P.I. Chemical blowing agents such as P-oxybisbenzenesulfonyl hydrazide (OBSH) and sodium bicarbonate can be used.

  Although a chemical foaming agent is used as the foaming agent, a fine injection foam molding (MuCell) method using a supercritical fluid as the foaming agent may be used. The fine injection foam molding method is a molding method in which nitrogen or carbon dioxide in a supercritical fluid state is dissolved in a molten resin under high pressure and then decompressed to generate a large number of fine bubbles. The under cover 1 may be molded using fine injection foam molding and core back molding. When the fine injection foam molding is used, the cavity of the foam layer 8 becomes smaller than when the chemical foaming agent is used.

  In the embodiment for carrying out the invention, the under cover 1 has been described as an example, but the present invention is applicable to any vehicle parts vehicle body.

DESCRIPTION OF SYMBOLS 1 Undercover 2 Main-body part 3 Attachment part 4 Attachment hole part 5 Attachment peripheral part 6 Skin layer 7 Skin layer 8 Foam layer 9 Cylindrical wall part 10 Top wall part 11 Solid layer 12 Mold 13 Fixed mold 14 Movable mold 15 Slide mold 16 Mounting hole projection 17 Molding space portion 21 High-hardness fiber 22 Synthetic resin material 23 Mica 24 Thickness of under cover 1 25 Thickness of skin layers 6 and 7 27 Thickness of foam layer 8 Test piece 32 Fixed frame 33 Fixed frame 34 Weight 35 The lower surface 36 of the weight 34 The removal part 41 The cylindrical body 42 The test body 43 The cover part 44 The power supply 45 The sound 46 The microphone 47 The sound 48 The microphone 51 The measurement sample 52 The measurement sample 53 The measurement sample 61 The under cover 62 The main body part 63 The attachment part 64 The attachment hole part 65 The skin Layer 66 Skin layer 67 Foam layer 68 Cylindrical wall portion 69 Top wall portion 70 Skin layer 71 Skin layer 72 Gradual change layer 73 Molding die 74 Fixed die 75 Movable type 76 Slide mold 77 Mounting hole projection 78 Molding space portion 79 Solid layer 80 Boundary portion

Claims (8)

  A cylindrical wall having a main body portion and a mounting portion formed by a core back molding method using a molding material made of a synthetic resin material, high-hardness fiber, and mica or talc, and the mounting portion protruding from the main body portion to the front side or the back side And a top wall portion that closes the opening that protrudes from the main body portion of the cylindrical wall portion to the maximum, and the mounting portion and the portion around the mounting portion of the main body portion as an unfoamed solid layer A vehicle component characterized in that a portion other than a portion around a mounting portion of a main body portion is constituted by a skin layer constituting a front and back surface portion and a foam layer constituting an intermediate portion between the skin layers.   2. The vehicle component according to claim 1, wherein the high-hardness fiber is glass fiber.   The vehicle component according to claim 1, wherein the synthetic resin material is made of a polyolefin resin.   4. The vehicle component according to claim 3, wherein the polyolefin resin is any one of a polypropylene resin, a polyethylene resin, and a mixed resin of a polypropylene resin and a polyethylene resin.   2. The vehicle part according to claim 1, wherein a rubber additive, mica or talc is added to the molding material.   The weight of the vehicle component is 1400 to 2000 g / m 2, the thickness of the skin layer is 0.2 to 0.5 mm, and the thickness of the vehicle component is 3 to 5 mm. Vehicle parts.   The vehicle component according to claim 1, wherein the foam layer has open cells.   The vehicle component according to claim 1, wherein a removal portion is provided in the skin layer.