KR101771580B1 - Door roller - Google Patents

Abstract

The present invention relates to a roller for a door of an electric vehicle, improving each mechanical characteristic of a roller unit and a body unit of the roller for a door of an electric vehicle while improving bonding performance between the body unit and the roller unit to endure severe load and repetitive opening and closing operation close to infinity of the door of the electric vehicle.

Description

{DOOR ROLLER}

The present invention improves the mechanical characteristics of the body portion and the roller portion of the roller for a railway car door, improves the adhesion performance between the body portion and the roller portion, and enables repeated opening and closing operations close to the infinitely- The present invention relates to a roller for an electric car door.

Generally, as shown in FIG. 1, a roller 14 is mounted on an upper portion of a door D for smooth sliding of a door.

Conventionally, a roller of a door of an electric motor vehicle is used in such a manner that a ball bearing is assembled at a central portion of an aluminum body portion and a roller portion of a plastic or urethane material is joined to an outer peripheral portion of the body portion.

However, due to the nature of the electric car door, repeated infinite opening and closing operations and severe load are continuously applied to the roller, the body part and the roller part are separated and detached, or the roller part of the plastic material is broken or the roller of urethane material is worn rapidly, When the noise is generated and a certain period of time is elapsed, the entire door may be shaken and there is a danger of a safety accident. In case of severe case, the opening / closing operation of the door may not be possible.

Conventionally, a knurled surface is formed on the outer circumferential surface of an aluminum body to attempt a physical coupling structure with a plastic or urethane roller portion. However, there is a problem that detachment phenomenon of the body portion and the roller portion still occurs.

Korean Registered Utility Model No. 20-0185692 "Roller for Electric Railway Entrance" (registered on April 4, 2000) Korean Utility Model Bulletin Bulletin No. 1996-0004192 "Sliding Door Roller for Electric Railway Vehicles" (Announced on June 5, 1996) Korea Public Utility Model Publication No. 95-14728 "Door Roller for Train"

The present invention has been conceived to solve the problems of the prior art as described above, and it is an object of the present invention to improve the mechanical properties of the body portion and the roller portion of the rollers for a railway car door, as well as improve the adhesive performance between the body portion and the roller portion, Which can withstand infinite repeated opening and closing operations and severe loads.

According to an aspect of the present invention, there is provided a roller for a motor vehicle door comprising: a ball bearing; a plastic-based body portion that is injection molded so that the ball bearing is inserted into the center portion; A roller portion which is a urethane elastic body; The roller portion may be formed of at least one selected from the group consisting of toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, modified 4,4'-diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, (Macroglycol) selected from the group consisting of polypropylene glycol (PPG), polytetramethylene glycol (PTMG), and mixtures thereof, and having an average molecular weight of 400 to 4,000, based on one equivalent of isocyanate selected from the group consisting of (PPG), 1,4-butanediol, and a mixture thereof is added to 100 parts by weight of the prepolymer, and the mixture is cured ; The body part is injection-molded by mixing 30 parts by weight of K-1575DG, a trade name of KOLON INDUSTRY CO., LTD, with 100 parts by weight of LAGOX TE5011, .

In the above, the isocyanate is selected from the group consisting of 4,4'-diphenylmethane diisocyanate, modified 4,4'-diphenylmethane diisocyanate, and mixtures thereof, and the polypropylene glycol (PPG) preferably has an average molecular weight of 1,000 to 3,000.

And a bearing support jaw which protrudes inward from both ends in the width direction of the bearing mounting ring and contacts the outer side in the width direction of the ball bearing, A plurality of connecting legs projecting radially outwardly apart from each other along an outer circumferential surface of the bearing mounting ring, and a plurality of connecting legs arranged concentrically with the bearing mounting ring, the inner circumferential surface having a larger diameter and a smaller width than the bearing mounting ring, And a roller portion engaging ring connected to an outer end of the connecting leg to form a plurality of roller auxiliary vacuum between the bearing mounting ring and the roller engaging ring; Wherein the roller portion is formed to fill the outer peripheral surface of the bearing mounting ring, the roller portion coupling ring, and the plurality of connection legs and fill the roller auxiliary vacuum; .

As described above, according to the present invention, not only the mechanical characteristics of the body portion and the roller portion of the roller for a railway car door are improved, but also the adhesive performance between the body portion and the roller portion is improved, To provide a new railway door roller bearing capable of withstanding.

1 is a perspective view of a door for a train,
FIG. 2 is a cross-sectional view of a doorway door roller for a railway vehicle according to an embodiment of the present invention,
Figure 3 is a front view of the body portion of Figure 2,
Figure 4 is a cross-sectional view taken along line AA of Figure 3;
5 is a sectional view taken along the line BB of Fig.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention in the drawings, portions not related to the description are omitted, and like reference numerals are given to similar portions throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

Hereinafter, an access door roller for a railway train according to an embodiment of the present invention will be described.

3 is a front view of the body portion of Fig. 2, Fig. 4 is a sectional view taken along the line AA of Fig. 3, Fig. 5 is a sectional view taken along line BB of Fig. 3, to be.

The main roller comprises a ball bearing (100), a plastic body (200), and a roller part (300) which is a polyurethane elastic body.

The body part 200 is formed by injection molding the plastic body part 200 while the ball bearing 100 is inserted into the injection mold so that the body part 200 is inserted into the center part of the body part 200, do.

Particularly, the body portion 200 of the present embodiment has a ring-shaped bearing mounting ring 210 in contact with the outer circumferential surface of the ball bearing 100, a ball bearing ring 210 protruding inward from both ends in the width direction of the bearing mounting ring 210, A plurality of connection legs 221 protruding radially outwardly from one another along the outer circumferential surface of the bearing mounting ring 210, a bearing mounting ring 210, The inner circumferential surface of which is connected to the outer end of the plurality of connecting legs 211 and is connected to the bearing mounting ring 210 by a plurality of roller- And a roller portion coupling ring 220 that forms a ring portion 222.

After the body portion 200 is injection-molded into the ball bearing 100, the roller portion 300, which is a polyurethane elastic body, is formed by a liquid-injection molding method so as to cover the outer circumferential surface of the body portion 200.

The roller unit 300 is formed to fill the outer circumferential surface of the bearing mounting ring 210 and the roller auxiliary engaging ring 220 and the plurality of connecting legs 221 and fill the roller auxiliary vacuum 222.

Thus, the main roller can improve the physical coupling force between the body part 200 and the roller part 300 through the roller auxiliary vacuum 222 and the roller part coupling ring 220.

Next, the manufacturing process of the body part 200 and the roller part 300 will be described.

First, the roller unit 300 will be described.

The roller portion may be formed of a mixture of toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, modified 4,4'-diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, (Macroglycol) selected from the group consisting of polypropylene glycol (PPG), polytetramethylene glycol (PTMG), and mixtures thereof and having an average molecular weight of 400 to 4,000, based on 1 equivalent of isocyanate selected from the group consisting of , And 5 to 90 parts by weight of a curing agent selected from the group consisting of polypropylene glycol (PPG), 1,4-butanediol, and a mixture thereof is added to 100 parts by weight of the prepolymer, followed by curing will be.

Preferably, the isocyanate is selected from the group consisting of 4,4'-diphenylmethane diisocyanate, modified 4,4'-diphenylmethane diisocyanate, and mixtures thereof. In this case, the conventional disadvantage that PPG or PTMG in a room-temperature liquid phase is used reduces the main physical properties such as tear, tensile, and heat resistance.

Preferably, the average molecular weight of polypropylene glycol (PPG) used as a curing agent is 1,000 to 3,000.

In general, the mechanical properties of rubber elastomers primarily depend on the hardness of the elastomer. As a method for increasing the hardness of the main liquid polyurethane resin while improving the abrasion resistance, there are a method of increasing the hard segment content in the prepolymer, a method of decreasing the molecular weight of polyol (also called macroglycol) There is a method of imparting ductility to a cured product by using an amine-based curing agent rather than a diol-based curing agent.

The polyurethane resin composition for use in the present roller is a polytetramethylene glycol (PTMG) which is a polyether polyol which is chemically more flexible than a polyester polyol during the synthesis of a prepolymer, a liquid phase at low temperature and a poly Propylene glycol (PPG), and mixtures thereof. In various embodiments, the hardness and abrasion resistance of the cured product are varied by controlling the molecular weight of the polyol, mixing polyols having different molecular weights, or varying the composition of the curing agent.

The polyurethane resin composition for the main roller is prepared by a casting method. The thermosetting polyurethane resin produced by the casting method is easy to control the physical properties by using a resin that maintains a liquid state at room temperature, The present invention is applicable to a polyurethane resin for a roller, which needs to be suitably controlled in physical properties to exhibit excellent mechanical properties.

Example  One

(1) Synthesis of prepolymer

94.8 g of polytetramethylene glycol having an average molecular weight of 450 was used to prepare a polyurethane resin composition. First, in order to remove moisture and the like in polytetramethylene glycol (PTMG), the polyol was heated to 100 占 폚 and defoamed for 1 hour and 30 minutes under a reduced pressure of 1 mmHg or less. The polyol was added dropwise to the previously heated modified 4,4'-diphenylmethane diisocyanate in a reactor fixed at 50 占 폚 over about 1 hour and reacted for 8 hours to measure the residual NCO% to synthesize a prepolymer.

(2) Equivalent amount of hardener

The synthesized prepolymer was degassed under stirring at 70 캜 under a reduced pressure of 1 mmHg for 45 minutes, stirring was stopped for the remaining 45 minutes, and the mixture was defoamed. An amount of the curing agent calculated according to the equivalent ratio r (NCO / OH) of the isocyanate curing agent at the time of defoaming was mixed. As the curing agent, 19 g of 1,4-butanediol was used.

In general, it is preferable that the curing agent is melted and defoamed by determining the heating or heating temperature range according to the curing condition.

(3) Curing of prepolymer

The molten prepolymer and the curing agent were mixed in a vessel and poured into a mold for preliminarily heated to 80 ° C within 3 minutes. The mixture was allowed to penetrate into the casting mold piece and cured at 100 ° C for 5 minutes. The cured polyurethane cured product was post cured in an oven at 130 캜 for 1 hour.

Preferably, if necessary, 0.001 to 5 parts by weight of a curing reaction catalyst such as a tertiary amine series, an organometallic series, an alkylphosphine series or an alkali metal series may be added to 100 parts by weight of the total resin amount.

(4) Investigation of mechanical properties

The hardness, tensile strength, tear strength, flexural strength and the like of the cured product produced in Example 1 were measured.

First, the hardness, the tensile strength, the tear strength and the flexural strength of the cured product of the finally prepared polyurethane resin composition were measured. A universal tensile tester was used to measure hardness, tensile strength and tear strength. The tensile strength (KS M 6782), the tear strength (KS M 6783) and the flexural strength (KS M 6695) were measured. The results are shown in the table.

In order to increase the efficiency of the mechanical properties, the same tests as those of Examples 2 to 6 were conducted again.

Example  2

Under the same conditions as in Example 1, 126 g of polytetramethylene glycol having an average molecular weight of 850 and 74.1 g of modified 4,4'-diphenylmethane diisocyanate were used to prepare a polyurethane resin composition. 13.4 g of 1,4 butanediol was used.

Example  3

Under the same conditions as in Example 1, a polyurethane resin composition was prepared by using 133 g of polytetramethylene glycol having an average molecular weight of 1000 and 66.7 g of modified 4,4'-diphenylmethane diisocyanate. 12 g of 1,4 butanediol was used.

Example  4

Under the same conditions as in Example 1, a polyurethane resin composition was prepared by using 150 g of polytetramethylene glycol having an average molecular weight of 1,500 and 50 g of modified 4,4'-diphenylmethane diisocyanate. 9.01 g of 1,4 butanediol was used.

Example  5

Under the same conditions as in Example 1, 172 g of polytetramethylene glycol having an average molecular weight of 3,000 and 28.6 g of modified 4,4'-phenylmethane diisocyanate were used to prepare a polyurethane resin composition. And 5.15 g of 1,4 butanediol was used.

Example  6

The experiment was carried out again using the polytetramethylglycol used in Example 3, which has comparatively good mechanical properties. As in Example 3, 133 g of polytetramethylglycol having an average molecular weight of 1000 was used, and 66.7 g of 4,4'-diphenylmethane diisocyanate was used. However, as a curing agent, 100 g of a polypropylene glycol copolymer having an average molecular weight of 1,500 in addition to 6.01 g of 1,4-butanediol was used to prepare a cured product.

Table 1 below shows the components and amounts used in Examples 1 to 6.

Table 1. Ingredients used in Examples 1 to 6 and their amounts used

Table 2 below shows the measurement results of the mechanical properties of the cured products prepared in Examples 1 to 6.

Table 2. Mechanical properties of the cured products prepared by Examples 1 to 6

As can be seen from the above Table 2, the cured products prepared according to Example 3 having a molecular weight of 1,000 of polytetramethylene glycol (PTMG) among the cured products produced by Examples 1 to 5 are medium in hardness Tensile strength, tear strength and flexural strength were the best. On the other hand, the cured product prepared in Example 6 using a mixture of polypropylene glycol and 1,4-butanediol having an average molecular weight of 1,500 as a curing agent was similar in hardness and tensile strength to the cured product prepared in Example 3 , The tear strength increased 1.5 times, and the flexural strength increased to 7.5 mm cracks at 100,000 cracks at 6000 cuts, and the flexural strength was significantly improved.

Example  7 to 12

On the other hand, in Example 3 showing good mechanical properties, experiments were also conducted using polytetramethylene glycol (PTMG) having an average molecular weight of 1,000. A prepolymer was synthesized using polypropylene glycol (PPG) having different molecular weights in addition to polytetramethylene glycol (PTMG) having an average molecular weight of 1,000, and a cured product was prepared using the prepolymer.

That is, a prepolymer was synthesized in the same manner as in Example 1 except that polytetramethylene glycol having an average molecular weight of 1,000 was used as a base and polypropylene glycol having an average molecular weight of 850 to 4000 was used to prepare a cured product. In Examples 7 to 11, 1,4-butanediol was used as a curing agent.

Tensile strength and tearing strength of the produced cured product were measured in Examples 1 to 6 above. On the other hand, in order to investigate the workability by liquid-phase retention at room temperature, the viscosity of the subject (prepolymer) and the curing agent was measured in each example. The viscosity was measured using a Brookfield LVTDV-II viscometer. The results are shown in Table 5.

As Example 12, polypropylene glycol having an average molecular weight of 1000 was used as the case of Example 8 having comparatively good mechanical properties, and in addition to 1,4-butanediol used in Examples 7 to 11 as a curing agent A cured product was prepared using polypropylene glycol (PPG). That is, a mixture of polypropylene glycol (average molecular weight 1,500) and 1,4-butanediol was used as a curing agent. In the case of Example 12, the physical properties of the base / curing agent and the mechanical properties of the cured product were also measured in the same manner as described above.

The following Table 3 shows the components and amounts of the components and the curing agent used in Examples 7 to 12, and the measured mechanical properties and physical properties are shown in Table 4 below.

Table 3. Ingredients used in Examples 7 to 12 and their amounts used

Table 4. Mechanical properties and physical properties of the cured products prepared according to Examples 3, 7 to 12

In Table 4, mechanical properties and physical properties are shown in the case of Example 3 in order to compare with the case of Example 3 using only PTMG as a subject.

The cured product prepared in Example 7 using PPG having an average molecular weight of 850 had the highest tensile strength and tear strength. However, in the case of Example 8, that is, when PPG having an average molecular weight of 1,000 was used as a subject, it also had relatively good tensile strength and tear strength.

On the other hand, as the molecular weight of PPG increased, physical properties (viscosity) of the subject increased. Comparing Example 8 and Example 12, it was found that the tensile strength and the tear strength were excellent in Example 8, and Example 12 in which PPG was mixed as a hardener was superior to Example 8 in which PPG was not used as a hardener, The viscosity was somewhat lowered, and the viscosity for the curing agent was somewhat higher.

According to the results, when polypropylene glycol having an average molecular weight of 1,000 was used (that is, in case of Example 8), the viscosity and viscosity were lower as the content and the molecular weight were increased than when polypropylene glycol having an average molecular weight of 2,000 was used The liquid is maintained at a low temperature near 0 ° C as well as the liquid at room temperature. As a result, it is possible to remove bubbles generated when applying to a roller manufacturing process at room temperature and to improve the flowability Processability and mechanical properties were also excellent.

As can be seen from Table 4, Examples 3, 7 and 8 are excellent when tensile and tear properties are taken into consideration. Among them, Example 3 is the most excellent. In the case of the viscosity which is the processing characteristic, the lower the viscosity that can be used when hand- The viscosities of Examples 3, 7 and 8 were similar when the discharge temperature of the resin was mechanically increased by 60 degrees with the physical properties first.

Comparative Example  1 to 3

PPG having an average molecular weight of 850 was used in Comparative Example 1, PPG having an average molecular weight of 2,000 was used in Comparative Example 2, and PPG having an average molecular weight of 1,500 was used in Comparative Example 1 in order to compare with the polyurethane resin composition for a roller- Adipate was used in Comparative Example 2, polyethylene adipate having an average molecular weight of 2,000 in Comparative Example 3, and polycarbonate diol having an average molecular weight of 2,000 in Comparative Example 3 in the same manner as in Example 1, . The hardener used herein was 1,4-butanediol, and the amount of the hardener used is shown in Table 5 below.

Table 5. Ingredients used in Comparative Examples 1 to 3 and their amounts used

Table 6. Mechanical properties of the cured products prepared by Comparative Examples 1 to 3

As can be seen from the above Table 6, it was confirmed that the tearing strength of Comparative Examples 1 to 3 was extremely low.

Next, the manufacture of the body part 200 will be described.

The body part 200 is obtained by injection molding 30 parts by weight of KOLON INDUSTRY CO., LTD., K-1575DG, with 100 parts by weight of LAGOX TE5011 (trade name).

The body part 200 has high tensile strength and low elongation so that it has excellent properties and has improved adhesion performance with the roller part 300.

Example  21

A test piece was injection-molded by mixing 30 parts by weight of a trade name K-1575DG of Kolon Industries Co., Ltd. with 100 parts by weight of LGO Chemical Co., Ltd., trade name LUPOX TE5011.

LUPOX TE5011 is a mixture of 4,4'- (1-methylethylidene) bis [phenol], 4- (1,1-dimethylethyl) phenylester and 40-50 wt% 1,4-benzenedicarboxylic acid polymer with 1,4-butanediol 35 to 45 wt%, others 10 to 15 wt%, and other additives 0 to 5 wt%.

Kolon Industries K-1575DG is known to consist of 70wt% of hexanedioic acid, 1,4-butanediol, p, p'-diphenylmethane diisocyanate polymer and 30wt% of glass fiber.

Comparative Example  21

The specimens were injection-molded by LUPOX TE5011, a trade name of LG Chem.

Tensile strength and Elongation  Measure

Tensile strength and elongation were measured four times for each of Example 21 and Comparative Example 21 according to KS M 3006, and the average values thereof are shown in the following table.

Table 7. Measurement of tensile strength and elongation for Example 21 and Comparative Example 21 division Example 21 Comparative Example 21 Tensile strength (kgf / cm2) 471.5 430 Elongation (%) 4.7 44

As apparent from the above table, Example 21 had a tensile strength increased by about 10% in terms of tensile strength compared with Comparative Example 21, and Example 21 had a tensile strength of about 90% as compared with Comparative Example 21 in terms of elongation, It was confirmed to have a decreased elongation.

The body portion The  adhesion Performance test

A plastic plate was prepared according to the physical properties described in Example 21 and Comparative Example 21, and a foil was laid on the plastic plate so that only half was adhered. The liquid polyurethane of Example 3 was poured and cured to prepare a specimen. Cut the test piece to a certain size (60 mm width, 120 mm length) and hold the end of the plastic and the end of the polyurethane, and pull the test piece at a speed of 5 kN at 500 kgf. Adhesion was judged to be defective when the adhesive was detached from the adhesive interface, or when the interface fell off, and the adhesive strength was higher than the adhesive strength of the adherend when the polyurethane part or plastic was broken, not at the adhesive interface.

Table 8. Adhesion performance test between the body part and the roller part division Example 21 + Example 3 Comparative Example 21 + Example 3 Result (Appearance judgment) Polyurethane breakdown Removal of adhesive interface

As can be seen from the above table, the adhesive surface of the polyurethane cured product of Example 3 was spread on the plastic plate of Comparative Example 21, but the plastic plate of Example 21 and the polyurethane cured product of Example 3 were polyurethane It was confirmed that the adhesive strength of the adhesive interface was higher than the breaking strength of the polyurethane.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the embodiments described above are intended to be illustrative, but not limiting, in all respects. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: Ball Bearing
200:
210: Bearing mounting ring
211: Bearing support jaw
220: Roller engaging ring
221: Connecting bridge
222: Roller auxiliary vacuum
300:

Claims (3)

A railway car door roller comprising:
And a roller part which is a polyurethane elastic body formed by injection molding so as to cover the outer circumferential surface of the body part, wherein the roller part is formed by injection molding a ball bearing,
The roller portion may be formed of at least one selected from the group consisting of toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, modified 4,4'-diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, (Macroglycol) selected from the group consisting of polypropylene glycol (PPG), polytetramethylene glycol (PTMG), and mixtures thereof, and having an average molecular weight of 400 to 4,000, based on 1 equivalent of isocyanate selected from the group consisting of (PPG), 1,4-butanediol, and a mixture thereof is added to 100 parts by weight of the prepolymer, and the mixture is cured ;
The body part is injection-molded by mixing 30 parts by weight of KOLON INDUSTRY CO., LTD. K-1575DG with 100 parts by weight of LGO chemical name LUPOX TE5011,
And a roller for a door of a train.
The method according to claim 1,
The isocyanate is selected from the group consisting of 4,4'-diphenylmethane diisocyanate, a modified product of 4,4'-diphenylmethane diisocyanate, and a mixture thereof,
Wherein the polypropylene glycol (PPG) used as the curing agent has an average molecular weight of 1,000 to 3,000.
3. The method according to claim 1 or 2,
The bearing mounting ring has a ring-shaped bearing mounting ring in contact with the outer peripheral surface of the ball bearing, a bearing supporting jaw protruding inward from both ends in the width direction of the bearing mounting ring and in contact with the outer side in the width direction of the ball bearing, A plurality of connecting legs protruding radially outwardly while being spaced apart from each other along an outer circumferential surface of the bearing mounting ring and having a diameter larger than that of the bearing mounting ring and having a smaller width, And a roller portion engaging ring connected to the end portion and forming a plurality of roller auxiliary vacuum between the bearing mounting ring and the roller mounting engaging ring;
Wherein the roller portion is formed to fill the outer peripheral surface of the bearing mounting ring, the roller portion coupling ring, and the plurality of connection legs and fill the roller auxiliary vacuum;
And a roller for a door of a train.

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