JP2003287064A - Electric disk brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve durability of a dust seal sealing a caliper body having an electric motor and an advancing and retreating mechanism, maintain the intrusion preventing effect against moisture, dusts and pebbles into a cylinder, and also to form the protection means for the dust seal with a simple composition and a low cost. <P>SOLUTION: The electric disk brake is provided with a caliper body 8 having the advancing and retreating mechanism advancing and retreating with a driving force of the electric motor 15 and generating the pressing force to the pressing member of the friction pads 3, 4, and brakes by slidably pressing the friction 3, 4 to the disk rotor 1 with the advancing and retreating mechanism. The space between an inner periphery of an opening part 45 of the caliper body 8 and an outer periphery of the pressing member is covered with an expansible dust seal 47. A guard member 52 covering the disk rotor 1 side of the dust seal 47 is provided on the outer periphery of the lower end of the opening part of the caliper body 8. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mounted on various vehicles such as automobiles and motorcycles, and a forward / backward moving mechanism for moving forward / backward by a driving force of an electric motor presses and slides a friction pad against a disc rotor for braking. It is related to the electric disc brake that is performed, and it prevents damage and wear of the dust seal that covers the opening of the caliper body, and maintains the effect of preventing water droplets, dust, and pebbles from entering the cylinder. .

[0002]

2. Description of the Related Art Conventionally, in various vehicles such as automobiles and motorcycles, an electric disk for moving a forward / backward movement mechanism by a driving force of an electric motor to push and slide a friction pad against a disk rotor for braking. There is a brake. In the caliper body of this electric disc brake, electric components such as the electric motor, a load sensor for measuring a load applied to the friction pad, a solenoid of a parking mechanism, and a rotation angle sensor for measuring a rotation angle of a rotating component, Rotating parts such as the advancing / retreating mechanism are internally provided. Then, in order to prevent the entry of obstacles such as water, dust, and pebbles into the caliper body, and to enhance the accuracy and durability of the operation of each of the above parts,
As in the invention described in Japanese Patent Publication No. 10-504876, there is a caliper body in which the opening of the cylinder is covered with a stretchable film-like dust seal. Further, such a dust seal is generally used in a hydraulic disc brake as in the invention disclosed in Japanese Utility Model Publication No. 5-35221.

[0003]

However, stones and other large obstacles on the road, muddy water, etc. are splashed up by the wheels and come into strong contact with the dust seal, causing damage or wear on the outer surface of the dust seal. However, there is a possibility that the sealing property is alienated. In particular, the dust seal was heavily loaded on the lower end side where the bridge portion was not guarded. Further, in the device described in Japanese Utility Model Publication No. 5-35221, baffle plates for cooling the brake fluid are arranged on both sides of the piston. By this air guide plate, it is possible to prevent the abutment of the obstacle with the dust seal to some extent. However, since this baffle plate is for cooling purposes, there is a problem in durability against collision of obstacles, and since the lower end side of the dust seal is not covered at all, the dust seal damage prevention effect was low. .

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems, and to provide a guard member capable of satisfactorily preventing pebbles and other obstacles from hitting a dust seal covering an opening of a caliper body. It is what
Then, it is possible to prevent the dust seal from being damaged or worn, and to maintain a good sealing property of the dust seal. Then, an electric disc brake having excellent accuracy and durability of operation is obtained by preventing malfunction and wear of the electric parts and the rotating parts installed in the caliper body.

[0005]

In order to solve the above problems, the present invention provides a caliper body with an advancing and retracting mechanism for advancing and retracting by a driving force of an electric motor to generate a pressing force on a pressing member of a friction pad. In an electric disc brake that presses and slides a friction pad on a disc rotor by this advancing / retreating mechanism, an expandable dust seal is provided between the inner periphery of the opening of the caliper body and the outer periphery of the pressing member. In addition, a guard member for covering the disk rotor side of the dust seal is provided on the outer periphery of the lower end of the opening of the caliper body.

Further, the guard member is closer to the disk rotor side than the advancing / retreating locus of the dust seal in the disk axial direction.
The friction pad and the caliper body may be arranged at a position where they do not interfere with the connecting bracket, and the opening of the caliper body may be partially or entirely covered so as to cover the outer periphery of the non-formation portion of the bridge portion.

[0007]

The present invention is configured as described above. Even when an obstacle, such as a small stone on the road, that can damage the dust seal is flipped up by the wheels in the dust seal direction while the vehicle is traveling, The guard member arranged on the outer periphery of the lower end of the opening of the body prevents the obstacle from colliding with the dust seal, thereby enhancing the effect of preventing damage to the dust seal. Further, the guard member can prevent the adhesion of muddy water and the like, and can also prevent the wear of the dust seal.

Therefore, the durability of the dust seal can be improved and the excellent sealing property can be maintained. The excellent sealing performance of this dust seal prevents moisture, dust, and pebbles from entering the caliper body for a long period of time, ensuring the accuracy and durability of the operation of interior parts such as electric motors and advancing / retreating mechanisms. Can be raised.

Further, the dust seal moves forward and backward in the axial direction of the disk as the forward and backward moving mechanism for pressing and sliding the friction pad moves forward and backward. Therefore, if the guard member is arranged at a position on the disc rotor side with respect to the trajectory of the dust seal in the disc axial direction so as not to interfere with the bracket connecting the friction pad and the caliper body, the guard member may prevent the dust seal from advancing and retracting. There will be no. Also,
The caliper body connected to the bracket also moves back and forth due to the reaction force of the forward and backward movement of the forward and backward movement mechanism, but by arranging the guard member as described above, the forward and backward movement of the caliper body is not hindered by the guard member. It is possible to move back and forth smoothly.

Further, it is possible to cover only a part of the outer periphery of the opening portion of the caliper body where the bridge portion is not formed, so that a low cost guard member can be obtained. Further, if the entire outer periphery of the non-formation portion of the bridge portion is provided so as to be covered, the cost is higher than the case of covering only a portion thereof, but a high dust seal guard effect can be obtained.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings. (1) is a disk rotor which rotates integrally with a wheel of an automobile and faces both friction surfaces (2). Figure 1
As shown in FIG. 3, a pair of friction pads (3) and (4) are arranged inside the tire wheel (5). Further, the bracket (6) is attached to the vehicle body so as to face the disc rotor (1).
Fixed to the caliper support arm (7) projecting from the fixed side by straddling the outer periphery of the disc rotor (1) to the opposite side,
The friction pads (3) and (4) are slidably arranged.

Further, as shown in FIG. 2, a pair of caliper bodies (8) for pressing the friction pads (3) and (4) against the disc rotor (1) are attached to the caliper support arms (7) of the bracket (6) as shown in FIG. It is connected via a slide pin (9) so that it can move back and forth. As shown in FIG. 1, the caliper body (8) includes an action portion (10) arranged on the back surface of one friction pad (3) with the disc rotor (1) sandwiched between it and the other friction pad (4). A reaction portion (12) provided with a reaction force claw (11) arranged on the back surface,
It is composed of a bridge portion (13) connecting the action portion (10) and the reaction portion (12) across the outer circumference of the disc rotor (1).

As shown in FIG. 1, the acting portion (10) is provided in the cylinder (14) with a brushless electric motor.
(15), a ball screw mechanism (16) for generating a pressing force of the friction pads (3), (4), and a deceleration for decelerating and transmitting the driving force of the electric motor (15) to the ball screw mechanism (16). It houses the gear mechanism (17). This reduction gear mechanism (17)
Is a planetary arm that can be rotated by the driving force of the electric motor (15).
(18), a planetary gear (23) pivotally supported on the planetary arm (18), and a sun gear (26) for rotating the planetary gear (23).

The planetary arm (18) is connected to the electric motor (1).
5) A cylindrical portion (20) having a magnet (39) acting as a rotor arranged on the outer periphery and a diameter larger than the cylindrical portion (20) and provided at the rear portion on the side opposite to the friction pad (3). Large diameter part
It consists of (21) and, by the driving force of the electric motor (15),
The inside of the cylinder (14) is rotatable via the bearing (57). Then, the planetary gears (23) are rotatably supported at three outer circumferences of the large diameter portion (21) at equal intervals, and as shown in FIGS. 1 and 2, each planetary gear (23) has a large diameter. The notch window (22) opened on the outer periphery of the portion (21) is projected to the outside. Further, as shown in FIG. 2, the large-diameter portion (21) has an adjacent planetary gear (2).
By cutting the outer circumference between 3) into a triangular shape, the weight of the planetary arm 18 can be reduced and the rotation angle sensor 19 described later can be used as a rotor.

The planetary gear (23) has a first gear (2).
4) and a second gear having a smaller number of teeth than the first gear part (24)
The gear part (25) is formed integrally by separating it in the front and rear in the axial direction, and the first gear part (24) is attached to the sun gear (26) fixed to the caliper body (8) in a non-rotatable manner. The sun gear (26) meshes with each other, and the planetary gear (23) can be rotated.

The fixing of the sun gear (26) is as shown in FIGS.
As shown in, the back plate (27) arranged at the rear of the caliper body (8) is provided with a plurality of through holes (29) at equal intervals, and the fixing pins (28) inserted through the through holes (29) are This is done by inserting it into the fixing hole (30) recessed in the back surface of the sun gear (26). The head of the fixing pin (28) is pressed by the cap (33) mounted in the mounting hole (32) of the back plate (27), and the inserted state in the fixing hole (30) is maintained. When the cap (33) is removed, the fixing pin
The fixing pin (28) is fixed in the fixing hole by the urging force of the pressing spring (31) mounted between the head of (28) and the back plate (27).
The sun gear (26) is released from (30) and the fixation of the sun gear (26) can be released.

Then, in the planetary arm (18), a bearing portion is provided.
The ball screw nut (34) of the ball screw mechanism (16) is housed through (58) so as to be rotatable and not movable back and forth. This ball screw nut (34) is the large diameter part of the planetary arm (18).
A reduction gear (35) having fewer teeth than the sun gear (26) is fixed to the outer periphery of the rear end arranged on the (21) side. This reduction gear (35) is replaced with the second gear part (25) of the planetary gear (23).
, And the ball screw nut (34) can be rotated by the rotation of the planetary gear (23). Then, in the ball groove (36) provided on the inner diameter side of the ball screw nut (34),
A ball screw shaft (38) is screwed through a plurality of balls (37) so as to be movable back and forth.

Further, the ball screw shaft (38) is provided at the tip,
As a pressing member of the friction pad (3), a flat pad pressing plate (40) is inseparably connected to each other. With this pad pressing plate (40), the friction pad (3) is pressed in a large area without concentrating the pressing force on a part, and the disc rotor is rotated.
It can be pressed in parallel with (1).

In this embodiment, the pad pressing plate is also used.
An expandable dust seal (47) is connected in a bellows shape between the outer periphery of (40) and the inner periphery of the cylinder (14) to form a cylinder.
The opening (45) of (14) is covered to prevent dust, water droplets, pebbles, etc. from entering the cylinder (14). In the present invention, in order to further enhance the sealing performance inside the cylinder (14), the ball screw shaft (38) and the pad pressing plate (40) are used in the present invention.
The connection with is made as follows.

First, as shown in FIG. 1, the ball screw shaft (3
In 8), the inside is formed in a hollow shape, a hollow portion (41) is provided, and a fixing wall (49) for fixing the mounting screw (42) is formed on the friction pad (3) side. Also, the pad pressing plate (4
A mounting hole (43) in the shape of a bag hole is recessed on the back surface of (0). Then, from the hollow portion (41) side of the ball screw shaft (38) to the mounting hole (43) of the pad pressing plate (40), the ball screw shaft (3
Attach the mounting screw (42) through the fixed wall (49) of 8),
The ball screw shaft (38) and the pad pressing plate (40) are connected.

With such a structure, the pad pressing plate (40) includes the inside of the cylinder (14) and the friction pad (3).
No hole or the like communicating with the outside on the side is formed, and the connection between the pad pressing plate (40) and the ball screw shaft (38) is covered with the pad pressing plate (40) and the dust seal (47). It will be done in the designated space. Therefore, the sealing property of the opening (45) of the cylinder (14) is improved, and it is possible to reliably prevent the intrusion of fine dust and a small amount of water droplets into the cylinder (14) from the friction pad (3) side. it can. Further, since the pad pressing plate (40) and the ball screw shaft (38) can be connected from the rear side of the caliper body (8), the assembling property and the maintainability are also improved.

In the present invention, the dust seal
As shown in FIGS. 1 and 4 to 6, the guard member (47) is attached to the outer periphery of the lower end of the cylinder (14) in order to prevent the (47) from being damaged or worn by adhesion of muddy water, collision of pebbles, and other obstacles.
(52) is provided. In the disc axial direction, the guard member (52) is arranged on the pad pressing plate (40) in a taper shape on the disc rotor (1) side with respect to the advancing / retreating locus of the dust seal (47) in the disc axial direction, as shown in FIG. Do not prevent the dust seal (47) that moves back and forth following it from moving back and forth. Further, in the width direction, the guard member (52) has an inner edge (53) formed in an arc shape so as not to interfere with the pad pressing plate (40) as shown in FIG. ) Is not disturbed. However, the guard member (52)
Is a pad pressing plate (40) in the disc axial direction.
The friction pad (3) having a wider width and the bracket (6) are arranged at a position where they do not interfere with each other, and damage or deformation due to collision with these members can be prevented.

Further, in this embodiment, as shown in FIG. 6, the guard member (5) is large enough to cover only a part of the outer periphery of the lower end of the dust seal (47) which is most susceptible to the bounce of small stones or the like.
2) is formed, but the opening (45) of the cylinder (14)
The guard member (52) may be formed so as to cover the entire outer periphery of the non-formed portion of the bridge portion (13). With such a guard member (52), the dust seal (47) has a higher guard effect.

In this embodiment, as shown in FIG. 1, a load sensor (48) is provided at the tip of the ball screw shaft (38),
The load on the friction pad (3) can be detected. Then, as shown in FIG. 1, a harness (50) connecting the load sensor (48) and the detector body (not shown) is inserted into the hollow portion (41) of the ball screw shaft (38). Further, the harness (50) is arranged in the hollow portion (41) with a sufficient length according to the moving distance of the ball screw shaft (38) in the forward and backward movements. However, there is a risk that the looseness of the allowance portion may enter into the gap between the components and cause catching or disconnection.

In order to solve this problem, as shown in FIGS. 1 and 3, the harness (50) is tension-biased by the tension spring (51), and the slack portion is always arranged in the hollow portion (41). The harness (50) is always tensioned outside the hollow portion (41). Even if the ball screw shaft (38) advances in the direction of the friction pad (3) and a tensile force is applied to the harness (50), the tensile spring (51) extends, so that the harness (50) may be disconnected. The forward movement of the ball screw shaft (38) is not hindered. Further, when the ball screw shaft (38) retracts, the tension spring (51) restores and contracts, so that the harness (50) does not loosen at any position other than the hollow portion (41).

The caliper body (8) has a planetary arm.
A brushless electric motor that detects the rotation angle of (18)
A rotation angle sensor (19) for controlling the drive of (15) and estimating the amount of forward / backward movement of the ball screw shaft (38) is provided. As shown in FIGS. 1 to 3, the rotation angle sensor (19) faces the outer peripheral surface of the triangular large diameter portion (21) of the planetary arm (18) on the inner peripheral surface of the cylinder (14), The magnetic coils are arranged circumferentially to form a stator, and the large diameter portion (2
1) is a rotor. Large part of this triangular shape
By rotating the inner circumference of the rotation angle sensor (19), a waveform output voltage is generated, so that the rotation angle of the planetary arm (18) can be detected. Thus, the planetary arm
Since the large diameter portion (21) of (18) can also be used as a rotor,
It is not necessary to provide a rotor for the rotation angle sensor (19) separately from the planetary arm (18), and it is possible to prevent an increase in the number of parts and the number of assembly steps.

Further, in this embodiment, as shown in FIGS. 1 and 3, the large diameter portion (21) of the planetary arm (18) is made to face the rear end surface of the planetary arm (18),
The back plate (27) is provided with a solenoid (54) of a parking mechanism. When the vehicle is parked, braking is performed by the friction pads (3) and (4), and the solenoid (5
When 4) is actuated, the locking pin (55) engages with the locking hole (56) provided on the end surface of the large diameter portion (21) of the planetary arm (18). By this engagement, the planetary arm (18) is fixed so that it cannot rotate, and the braking by the friction pads (3) and (4) can be maintained. A cover cover (44) is attached to the outer periphery of the back plate (27) through an O-ring (60) to protect the solenoid (54), the back plate (27), and others from external shocks, and The sealability on the back plate (27) side in (14) is also improved.

Further, in this embodiment, the reduction gear mechanism (17) is connected to the friction pad via the electric motor (15) as described above.
(3) Since it is arranged on the side opposite to (4), it becomes difficult for the braking heat to be transmitted to the reduction gear mechanism (17), and it is possible to prevent the reduction gear mechanism (17) from becoming hot. In order to prevent the temperature of the parts from rising due to the transmission of such braking heat, in this embodiment, the caliper body (8) is provided on the friction pad (3) side and the reduction gear mechanism (17) side of the electric motor (15). It is divided into three parts, and the caliper body is placed between each part as shown in Fig. 1.
Insulation ring member made of heat insulating material with lower thermal conductivity than (8)
(46) is inserted and arranged to enhance the heat insulating property of the caliper body (8). Due to the heat insulating ring member (46), the braking heat of the friction pads (3) and (4) is transferred via the outer surface of the caliper body (8) to the electric motor (15), the rotation angle sensor (19), the solenoid (54). ) Etc., and reduction gear mechanism (17)
Can be effectively prevented from being transmitted to. It is also possible to prevent the driving heat of the electric motor (15) from being transferred to the reduction gear mechanism (17).

Therefore, the electric motor (15), the rotation angle sensor
(19), electric parts such as solenoid (54), reduction gear mechanism
(17), etc. are prevented from becoming high temperature, the accuracy and durability of the operation of each of the above-mentioned parts are improved, and smooth braking of the electric disc brake becomes sustainable for a long period of time. Since the heat insulating ring member (46) is formed by dividing the main body of the caliper body (8) and is inserted and arranged between the respective parts, it is easier to assemble as compared with the case where the caliper body is provided inside the parts. It is easy and does not affect productivity. In addition, the split formation also improves the assemblability and maintenance of various components inside the caliper body (8).

Further, as described above, the electric motor (15) is built in the caliper body (8), and the reduction gear mechanism (17) such as the planetary gear (23) is not provided inside the electric motor (15). Since the caliper body (8) is arranged on the rear side of the electric motor (15), the caliper body (8) is neither elongated nor large in diameter, and can be formed compactly. Therefore, the degree of freedom in layout when the electric disc brake is installed inside the tire wheel (5) is increased.

In the electric disc brake constructed as described above, when the driver of the automobile depresses the brake pedal to perform the braking operation, the electric motor (15) is driven according to the depression amount, and the planetary arm (18) ) Rotates in the cylinder (14). Due to the rotation of the planetary arm (18), the large diameter portion (2
A planetary gear (23) which is axially supported by 1) and which meshes the first gear portion (24) with the sun gear (26) rotates around the outer periphery of the sun gear (26). The rotation of the planetary gear (23) causes the second gear part to rotate.
Ball screw nut that engages reduction gear (35) with (25)
(34) is rotated.

Then, by the action of the ball screw mechanism (16), the turning force is converted into the sliding force of the ball screw shaft (38),
The friction pad (3) on the working portion (10) side is pressed and slid through the pad pressing plate (40) and pressed against the disc rotor (1). Furthermore, the caliper body (8) retracts due to the reaction force of the sliding of the ball screw shaft (38), and the reaction force claw (11) of the reaction portion (12).
, Press and slide the friction pad (4) on the reaction part (12) side,
Braking is performed by pressing the disc rotor (1).

At the time of this braking, as described above, the planetary gears are used.
(23) is the first gear part (24) that meshes with the sun gear (26)
The number of teeth of the second gear part (25) that meshes with the reduction gear (35) of the ball screw nut (34) is smaller than that of the sun gear (26) in this second gear part (25). The reduction gear (35) having a small number of teeth is rotated. Due to these actions, the driving force of the electric motor (15) can be efficiently decelerated and converted into a strong pressing force of the friction pads (3) and (4), and effective braking can be performed.

When the brake pedal is released, the planetary arm (18) rotates in the reverse direction under the control of the electric motor (15), and the ball screw nut (3) is passed through the planetary gear (23).
Since 4) rotates in the opposite direction to the previous rotation, the ball screw shaft (38) retracts, and the pressing of the friction pad (3) is released. Also, due to the reaction force of this ball screw shaft (38) retracting,
The caliper body (8) also slides in the restoring direction, and the reaction part (1
Since the pressing of the friction pad (4) on the 2) side is released, the braking is released.

Then, even if an obstacle such as muddy water or pebbles is splashed up by the electric disc brake of the present invention on a wheel or the like while traveling, a guard member (52) provided on the outer periphery of the lower end of the cylinder (14). The dust seal (47) can be effectively prevented from hitting the dust seal (47) by an obstacle, and the dust seal (47) can be highly prevented from being damaged or worn. Then, while covering the opening (45) of the cylinder (14) with the dust seal (47) having excellent durability,
Since the ball screw shaft (38) and the pad pressing plate (40) are connected so as not to communicate with the friction pad (3) side,
It is possible to favorably prevent intrusion of water, small stones, dust, fine dust, small amount of water droplets, etc. into the cylinder (14).

Therefore, the electric motor (15), the solenoid (54), and the load sensor (4) installed in the caliper body (8).
8), electrical products such as rotation angle sensor (19), ball screw mechanism (16), reduction gear mechanism (17) and other rotating parts can be satisfactorily prevented from malfunctioning, deterioration of grease and wear of parts. Become. In addition, the caliper body when braking or releasing braking
(8), the ball screw shaft (38), the friction pad (3), etc. can be smoothly moved forward and backward without the guard member (52) interfering with the electric disk brake. The operation accuracy and durability are improved.

[0037]

The present invention is constructed as described above, and since the opening of the caliper body is covered with a dust seal to enhance dustproofness and waterproofness, muddy water, pebbles, dust, etc. inside the caliper body, Intrusion of a little water and fine dust,
It can be prevented well. In the present invention, since the dust seal excellent in sealing performance is protected by the guard member provided on the outer periphery of the lower end of the opening of the cylinder, damage and wear of the dust seal can be effectively prevented, and a high dust seal can be obtained. The sex can be maintained for a long time. Therefore, it is possible to prevent malfunction and wear of the electric motor, other electric products, the advancing / retreating mechanism, and other rotating parts arranged in the cylinder, and the accuracy and durability of the operation of the various members. It will be improved. Further, as described above, the guard member having a high effect of preventing dust seal damage and wear can be easily formed with a simple configuration, and a low-cost product can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an electric disc brake installed facing a disc rotor according to an embodiment of the present invention.

2 is a cross-sectional view taken along the line AA of FIG. 3, in which the fixing pin of the sun gear and the harness are omitted.

FIG. 3 is a partially enlarged cross-sectional view of the back plate side of FIG.

FIG. 4 is a partially enlarged sectional view of the vicinity of the guard member in FIG.

FIG. 5 is an exploded perspective view of a caliper body and a guard member.

FIG. 6 is a cross-sectional view of a caliper body provided with a guard member.

[Explanation of symbols]

1 disk rotor 3 friction pad 4 friction pad 6 bracket 8 caliper body 13 Bridge section 15 Electric motor 45 opening 47 dust seal 52 Guard member

Claims (2)

[Claims] 1. A caliper body is provided with an advancing / retreating mechanism for advancing / retreating by a driving force of an electric motor to generate a pressing force on a pressing member of a friction pad, and the advancing / retreating mechanism presses and slides a friction pad on a disc rotor. In an electric disc brake for braking, a space between the inner circumference of the opening of the caliper body and the outer circumference of the pressing member is covered with an expandable dust seal, and the outer circumference of the lower end of the opening of the caliper body is covered by the dust seal. An electric disc brake characterized by having a guard member covering the disc rotor side. 2. The guard member is arranged at a position not interfering with a bracket connecting the friction pad and the caliper body on the disc rotor side with respect to the advancing / retreating locus of the dust seal in the disc axial direction, and at the opening of the caliper body, The electric disc brake according to claim 1, wherein a part or all of the outer periphery of the non-formation portion of the bridge portion is provided so as to be covered.