JPH0613884Y2 - Grating - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to a grating to be fitted on the upper surface of a circular waterway block used for a gutter of a road or the like.

2. Description of the Related Art A circular water channel block is a concrete block having a substantially square columnar shape, a circular drainage hole passing through in the longitudinal direction, and an upper opening communicating with the drainage hole. Such blocks are buried near the surface of the earth so as to be continuous in the vertical direction. For circular canal blocks with a narrow upper opening, leave this opening. When making a gutter, use a circular channel block with a wide upper opening. In this case, grating is used to close the upper opening. FIG. 10 shows a sectional view. The width of the opening is often 80mm, but this can be changed. Surface water enters the circular drainage hole through the grating hole and flows there to be drained. A large number of circular waterway blocks are continuously buried in the longitudinal direction. Naturally, a large number of gratings must be continuously installed on the block opening in the longitudinal direction. Conventionally, the grating is made of iron. For example, a thin plate material is bent to form a frame on four sides, a vertical crosspiece is made of the plate material, and a thin crosspiece is passed in the horizontal direction. The iron one is robust and can be ridden by car tires or humans. Also, since it is heavy, it is safe without being removed from the opening of the block. It does not deteriorate due to sunlight or rainwater and has a long life. It has the advantage that it has a proven record.

[Problems to be solved by the device]

However, such a product has many welding points and is troublesome to manufacture, which is troublesome. In addition, it must be painted to prevent rust. It is also heavy and difficult to handle. Further, since iron objects cannot be fixed to the opening of the block, an unpleasant rattling noise is generated when an automobile passes over it. Although measures such as galvanizing have been made to prevent rust, it often happens that the plating comes off and rusts over the years. It is an object of the present invention to provide a grating that is easy to manufacture, inexpensive, does not generate noise, is easy to handle, and is free from rust.

[Means for Solving the Problems]

The grating of the present invention does not weld an iron material, but kneads and heats a mixture of a thermoplastic resin and an inorganic powder and granules and molds it by a mold. The weight ratio w of the thermoplastic resin is 0.3 to 0.7
Is. In other words, in terms of the weight ratio x of the thermoplastic resin and the inorganic powder particles,
That is 70/30 to 30/70. Wt% of thermoplastic resin
If this is expressed by p, it means that 30 ≦ p ≦ 70.
If this is expressed in% by weight of inorganic powder granules, 30 ≤ m ≤ 70
That's what it means. 30/70 ≦ x ≦ 70/30 is the above 2
It is a simple expression of three expressions. These relations are P = 100w, p + m = 100, w = x / (1
+ X). Further, on the side surface of the grating, a suitable number of side protrusions whose cross section becomes smaller as it goes downward are formed. Further, the end face in the longitudinal direction of the grating has a length of w / 1000 to w / 100 of the grating length L, and the average width is 1 of the end face width M.
Form end ridges that are / 300 to 1/30. Since it is of course a grating, a proper number of through holes are formed in the vertical direction.

[Action]

Since the mixture of the thermoplastic resin and the inorganic powder granules is molded using a mold to give the grating, the whole is manufactured at once. As the thermoplastic resin, polyethylene, polypropylene, polyvinyl chloride, polystyrene, nylon, polyester or the like can be used. Also, waste plastic and recycled products can be used. As the inorganic powdery granules, calcium carbonate, talc, silica sand, glass fibers and the like can be used. However,
For molding, it is desirable that the particles have a uniform particle size to some extent. The reason for mixing the inorganic powder particles is as follows. By adding an inorganic powder granule, it is possible to increase rigidity and impart mechanical strength. Since plastic alone is too light, some weight is required and for this purpose inorganic powder granules are added. If it is only plastic, it will be decomposed and deteriorated by sunlight, but if inorganic powder particles are added, the light will be blocked and the light resistance will increase. It is also strong against rainwater. By adding inorganic powder particles, the amount of plastic can be saved and the material cost can be reduced. Since such an effect is obtained, inorganic powder granules are added. In order to have such an effect, the weight ratio of the thermoplastic resin is% p
Must be 70% or less. Beyond this,
Since the amount of inorganic powder particles is small, the ultraviolet shielding effect is reduced and deterioration occurs. However, if the amount of plastic is too small, plastic molding becomes difficult. Therefore, the weight% p of the thermoplastic resin is
It is limited to more than 30%. Forming side protrusions having a smaller cross-sectional area on the side surface of the grating has the following effects. The grating fits in a groove having substantially the same width as the grating, but the side protrusion is pushed by the side wall of the groove and deforms from the middle. The elastic force of this deformed portion causes the grating to come into close contact with the groove. Therefore, the grating cannot be easily extracted. In addition, there is no rattling and no noise even when a car etc. passes through. The effect of the longitudinal end ridges of the grating is to absorb the effects of thermal expansion. One end ridge may be provided at the center, or a plurality of end ridges may be provided at positions symmetrical with respect to the grating center. There may be a plurality of asymmetrical positions. It is assumed that the length is q and the average width is u. When there are one end ridge at the center or a plurality of end ridges at positions symmetrical with respect to the center of the grating, when the grating is fitted into the groove, a gap of 2q is generated between the adjacent gratings. The problem is when it is constructed in winter. In summer, it expands because it is plastic. However, since there is originally a gap of 2q, the expansion can be absorbed by this. For this to happen, the width u of the end ridge must be narrow and easily deformable. Therefore, the width u is set to 1/300 to 1 to 30 of the grating width M. The end ridges may be in asymmetrical positions. In this case, the gap created during grating is q. When the temperature difference between summer and winter is ΔT, the coefficient of thermal expansion is γ, and the total length is L, the length of expansion and contraction is γLΔT. This is 2q, or q
It is better if the degree is smaller or smaller.

【Example】

The grating of the present invention will be described with reference to the drawings illustrating the embodiments. 1 is a perspective view of the whole, FIG. 2 is a plan view, FIG. 3 is a front view, FIG. 4 is a side view, and FIG. 5 is a sectional view taken along line VV in FIG. 2, FIG. FIG. 7 is a sectional view taken along line VI-VI and VII-VII in FIG. The grating 1 is formed by kneading and heating a mixture of a thermoplastic resin, an inorganic powder granule, a pigment and the like and molding the mixture by an injection molding method. It has the shape of an elongated rectangular plate. Length L in this example
= 500 mm, width M = 76 mm, and height H = 38 mm. The width M is determined by the width of the opening groove of the circular water channel. Since this is 80 mm, M = 76 mm. The length L is arbitrary,
If the length is too short, the number will increase and the construction will be troublesome. Therefore, the slenderness ratio L / M is set to 3 or more. The upper surface 2 and the lower surface 3 are parallel planes, but there are a plurality of through holes 4 between the upper and lower surfaces. This is for passing surface water. In this example, the elongated through holes 4 are regularly arranged vertically and horizontally, but the size and distribution of the through holes are arbitrary. The grating 1 is formed by parallel side frames 5 and 5, and end frames 6 and 6 which are perpendicular to the side frames 5 and 5 and are short. In this, two vertical bars 7 parallel to the side frame 5 are arranged in the vertical direction, and are 3 at a right angle to the side frame 5.
The horizontal crosspiece 8 of the book exists in the horizontal direction. Furthermore, the auxiliary cross rail 9 also exists in the lateral direction. These structures are arbitrary. What is important is that the side surface 10 is formed with the side projections 11 and the end surface 12 is formed with the end projections 13. The side protrusions 11 are protrusions whose cross-sectional area becomes smaller as they go downward. FIG. 8 shows a partial plan view of the side protrusion 11. When the protruding height at the upper end of this is S, the distance N on the upper surfaces of the left and right side protrusions 11 is (M + 2S). This is clearly shown in FIG. M is the width of the grating, and the width of the lower surface is also M. If the width of the groove into which the grating is to be inserted is W, the inequality M>W> M (1) is satisfied. With such a relationship, when the grating 1 is put into the groove (width), it is inserted into the groove at first, but stops when the side protrusion 11 comes into contact with the groove. After that, the grating 1 is hammered in with a wood hammer or the like. Then, the upper half of the side protrusion is distorted and the grating is completely inserted into the groove. Fig. 10 shows a cross-sectional view taken into the groove. A circular waterway block 20 is buried near the surface of the earth. A drainage circular hole 21 continues in the central axis direction. There is an opening groove 22 communicating with this from above. In the grating 1, the bottom surface 3 is the stepped portion 23,
The side surface 10 is supported by the side wall 24 of the opening groove 22.
However, the side surface 10 does not actually contact the side wall 24. FIG. 11 shows an enlarged view of this portion. Since the grating width M is smaller than the groove width W, the side surface 10 and the side wall 24
A void is created between the two. However, the upper ridge 11 is distorted
Is in contact with the side wall 24 of the groove 22, so that there is no rattling. In this example, W = 80mm, M = 76mm, S = 3mm, N = 82mm
I am trying. The upper half of the side protrusion 11 is crushed by about 1 mm. The end protrusion 13 of the end face 12 is located at the center in this example.
As shown in FIG. 12, when such gratings are fitted in the opening groove 22 in order, two times the height q of the ridge between the end faces is doubled.
A gap G of q is generated. If it was constructed in winter, it is plastic and will expand in summer. If the end protrusions 13 are not provided, the gratings are pressed against each other due to the expansion, and a part of the grating is lifted from the groove. However, in the present invention, a 2q void is always generated during construction. When thermally expanded, the end protrusions are crushed and the gap G is narrowed, but the gratings do not press each other and rise. In this example, as shown in FIG. 9, the height q of the end protrusion 13 is
The minimum width u ₁ is 0.5 mm, the maximum width u ₂ is 1.0 mm, and the average width u is 0.75 mm. The minimum width of the end protrusions may be such that they contact the end faces of the adjacent gratings during construction and do not collapse. In addition, if two adjacent end ridges of the grating are butted, the width must be such that they match. This may be about 1/300 or more of the end face width M. The maximum width of the end ridges is determined by the condition that when the grating is thermally expanded, it can be collapsed to shrink the voids. The force generated on the end face due to thermal expansion is, of course, proportional to the cross-sectional area of the grating. Therefore, the maximum width of the end ridge is proportional to the grating width. The ratio of the maximum width of the end protrusions to the grating width M is about 1/30. The most important parameter is the length q of the end protrusion 13. This should be similar to the thermal expansion and contraction width of the grating length in summer and winter. The densities of the thermoplastic resin and the inorganic powder particles are ρ and ζ, and the linear expansion coefficients are α and β. The weight% p of the whole thermoplastic resin is 100w. w takes a value of 0 to 1 and can be said to be the weight ratio of the thermoplastic resin. Since this is not a commonly used word, the relation with x, p and m is shown on page 4. These mixtures do not change their physical properties by mixing. Therefore, it is considered that the effective linear expansion coefficient γ of the grating is a weighted average of the linear expansion coefficients depending on the volume ratio of the mixture. From this reasoning, It turns out that. There are various types of thermoplastic resins. Coefficient of thermal expansion α
Although it cannot be said unequivocally that there are various kinds of substances and the same substances may differ depending on the conditions, it will be about 0.5 to 2 × 10 ^-4 K ^-1 . The coefficient of thermal expansion β of the inorganic powder granules varies, but it will be on the order of 10 ^-6 K ^-1 . Also, the density is various, but the density ρ of plastic is 0.9
At about 1.6, the density ζ of the inorganic powder particles will be about 2-3. β can be ignored for α. Then the effective coefficient of linear expansion γ is Can be written. In the present invention, the weight% p (100w) of the thermoplastic resin is 30
Since the content is ˜70 wt%, 0.3 ≦ w ≦ 0.7. For example, if ρ = 1 gcm ^-3 and ζ = 2 gcm ^-3 , the second term of the denominator will be smaller than the first term, and if this is dropped for simplicity, It turns out that. Let ΔT be the temperature difference between cold and warm in summer and winter.
Since the grating has the length L, the expansion / contraction magnitude δ
Is It means that. The physical property constant is α = (0.5 to 2) × 10 ^-4 K ^-1 ζ = 2 to 3 gcm ^-3 ΔT = 30 to 80 K ρ = 0.9 to 1.6 gcm ^-3 , so the expansion rate in the longitudinal direction Is Becomes When abutting ridges of adjacent gratings are brought into contact with each other, the air gap becomes 2q, but since this is about the same as δ, q / L is a value of (15 to 150) × 10 ^-4 w (7). Good. However, since the approximation of ignoring the second term of the denominator in equation (3) above is performed, this correction is approximately
Evaluated as 2/3, q / L is Can be thought of. In this example, q = 1.5mm, L = 500mm
So, q / L = 3/1000. In reality, the linear expansion may be further reduced depending on the shape and distribution of the through holes 4. If the area of the through hole 4 is large, the peripheral portion can absorb the expansion, so that the amount to be absorbed by the end protrusion may be slightly reduced. In this example, the through holes 4 are arranged 3 × 8 vertically and horizontally, but not limited to this, a large number of round holes may be arranged like a puddle. As described above, the end protrusion 13 is an important element of the present invention, but this is an ingenuity necessary because the material is plastic. Conventionally, since the iron grating is used, thermal expansion is small, and such consideration is unnecessary.

[Effect of device]

(1) Since it is made of inorganic powder particles and a thermoplastic resin, it can be manufactured at a lower cost than iron-made grating. Material costs can be reduced by using waste plastics and recycled products. Also, since it is molded using a mold, it can be manufactured at once. It is extremely simple compared to making plate materials by welding like iron products. (2) The iron grating is quite heavy even if the area of the through hole is large. The specific gravity of the grating of the present invention can be freely designed depending on the mixing ratio. It is considerably lighter than the iron one. For example, a product with a specific gravity of 1.2 to 1.8 can be easily made. It is light and easy to handle. It is advantageous in all aspects such as transportation, storage and mounting. (3) Excellent weather resistance because it contains inorganic powder particles. Ultraviolet rays are also shielded and the plastic does not deteriorate. This effect is enhanced by adding black pigment to blacken the whole. (4) Since it contains inorganic powder particles, it has superior mechanical strength compared to plastic alone. (5) Plastic has a large thermal expansion and contraction, but since it has end ridges, it can leave a gap between adjacent gratings when it is attached to the groove. This makes it possible to absorb the effects of thermal expansion and contraction. (6) When there is a side protrusion on the side surface and the grating is fitted in the groove, the upper half of the side protrusion bends and comes into close contact with the groove wall. Therefore, the grating cannot be easily removed. Moreover, even if a car passes through, it is not rattling. No rattling, so no noise.

[Brief description of drawings]

FIG. 1 is a perspective view of a grating according to an embodiment of the present invention. FIG. 2 is a plan view of grating. FIG. 3 is a front view. FIG. 4 is a side view. FIG. 5 is a sectional view taken along line VV in FIG. FIG. 6 is a sectional view taken along line VI-VI in FIG. FIG. 7 is a sectional view taken along line VII-VII in FIG. FIG. 8 is a partial plan view of the side protrusion. FIG. 9 is a partial cross-sectional view of the end ridge. FIG. 10 is a cross-sectional view showing a state where the circular waterway block is fitted with the grating. FIG. 11 is a partially enlarged cross-sectional view showing the distortion of the side protrusions in the fitted state. FIG. 12 is an enlarged plan view of the abutting portion of the end protrusion when the grating is fitted. FIG. 13 is an enlarged plan view of the state where the grating is expanded and the end ridges are crushed. 1 …… Grating 2 …… Top surface 3 …… Bottom surface 4 …… Through hole 5 …… Side frame 6 …… End frame 7 …… Vertical rail 8 …… Horizontal rail 9 …… Auxiliary horizontal rail 10 …… Side surface 11 …… Side ridge 12 …… End face 13 …… End ridge 20 …… Circular channel block 21 …… Drainage circular hole 22 …… Opening groove 23 …… Step 24 …… Side wall G …… Void

Claims (1)

[Scope of utility model registration request] 1. A thermoplastic resin and an inorganic powder granule, which are produced by integrally kneading and heating as a raw material a mixture of the thermoplastic resin in a weight ratio w of 0.3 to 0.7. Yes, it has a rectangular plate shape with an aspect ratio of 3 or more, and has a plurality of through holes that penetrate vertically, and has a suitable number of side protrusions on the side surface whose cross-section decreases as it goes downward. Is the whole length L of w / 1000 to w / 100, and the average width is 1 of the end face width M.
Grating characterized by having end projections of / 300 to 1/30 on the end face in the longitudinal direction.